What kind of shooting are you looking to do in your basement? Pistol, rifle, or shotgun? Just target shooting or more tactical shooting practice while on the move? I really can't begin to comment about airguns as I have no experience with them. Airsoft though is something I know well and as a training aid it could definitely be worthwhile. That was the purpose of airsoft to begin with several decades ago, force on force training with totally non-lethal weapons.
I will not misinform you and tell you they're laser accurate, but they could definitely be useful for target practice inside of your 60ft basement. I have several Chinese clone AEGs(automatic electric guns, basically the main battle rifles of the airsoft world) and with each of them I can fire fully automatic bursts across my 75ft yard and keep all shots within a 6 inch area, and that's without any mods whatsoever like tightbore barrels and high quality hop ups(the two mods most likely to increase your accuracy). Any good quality Chinese clone AEG should serve you well. I'll get to which ones to purchase in a moment.
As for pistols, well, they're usually no where near as accurate in the airsoft world. You have three basic types, spring, gas, and electric. If you go the electric route, make sure it's an AEP(automatic electric pistol) from either CYMA or Tokyo Marui and be sure it has a metal gear box, not one of those completely useless plastic turds that you find at Walmart. These can be fun and are very cheap($50 or so for a CYMA Glock replica which is a good choice) and easy to use(just charge the battery when it dies, no need to refill with gas). However they're performance is rather lacking compared to gas pistols in that they have far less power and thus range.
Gas pistols can be quite powerful for airsoft guns, easily equaling AEGs in sheer power, but they are subject to all kinds of issues like leaky mag reservoirs and of course don't function well in cold temps. Don't buy cheap gas pistols as they will almost certainly give you issues. Expect to pay at least $100 for a quality gas pistol and if you do, you shouldn't have too many issues. I don't have much experience with them myself.
Spring pistols are the lowest common denominator of airsoft guns. They range anywhere from .50c or so(seriously) up to about $20 for the more expensive ones. Honestly though a few bucks can net you a good one. I bought a cheap full metal Beretta M92 replica off a wholesale dealer for $6 and it has been one of my favorite airsoft guns surprisingly. It's accurate inside of about 30ft but accuracy goes all to hell after that. It works fantastically for feline discipline though(it won't hurt them any more than a swat on the nose, just don't aim for their face as you could hit their eyes) and I keep this one on my nightstand for just such a purpose.
Realistically though, avoid these if you're looking for accuracy, especially at 60ft. They're nothing but toys.
As for shotguns, your choices are very limited as there really are no truly realistic shotguns in the airsoft world. If you want safe practice with your shotgun, you'd probably be better served by reloading 12G shells with some cheap walmart airsoft BBs and a very light powder load. If you just want some practice with working a pump and shooting while on the move, then a cheap airsoft shotgun could work perfectly well. Go for a UTG/Double Eagle brand 870 clone. They only fire one BB at a time(see what I mean by unrealistic shotguns) but they work and they're cheap, like less than $15 at wholesalers cheap.
Airsoft sniper rifles are nothing but big spring or gas guns and while they can be quite accurate, lack the fun factor of the AEGs and aren't so much more accurate as to make them worth the money, IMHO. I own a couple though and don't regret it.
I think you'll probably be most pleased if you stick to the AEG route. These are fully automatic(and semi too of course) and come in a variety of flavors that cover pretty much every kind of military rifle and SMG you can imagine. You could easily spend $3-400 on a high quality brand like Tokyo Marui or Classic Army, or even the uber-expensive brands such as VFC, Systema, etc., which could cost anywhere form $600 to well over a thousand dollars. There's just no point to these though for a more casual airsofter as there are a huge number of Chinese clone manufacturers which copy the designs from Tokyo Marui and others(To the point that nearly all parts swap over from different brands) and are usually on par or often even surpass the quality of the higher priced offerings for a fraction of the price, anywhere from about $75 up to perhaps $200 for the very nice full metal construction rifles with all the bells and whistles.
Someone in this thread already mentioned the Echo 1 brand guns, and these are good, however, they are literally nothing more than rebranded JG(Jing Gong) offerings. Just cut out the middle man and buy JG directly as you will probably save $30-$50 in the process. As for what to buy, anything from either JG or CYMA is good and you can't go wrong. The lemon rate among these two manufacturers is incredibly low and almost all their range have 100% compatibility with Tokyo Marui parts, meaning there is a HUGE selection of aftermarket goodies from stuff to make them more accurate to parts that make them look more tacticool. Just a warning though, CYMA used to make crap guns a few years ago, so make sure the model designation you're looking at is at least CM.027 or higher. Anything with a number lower than that has plastics internals and is in fact not a real AEG and is instead on par with the airsoft toys you can buy at Walmart, meaning it WILL break on you, period. Just buy CM.027 and up and you can't go wrong. JGs are just good period. Be sure to buy some low capacity or mid capacity magazines, not the high caps, that way you can get more practice changing mags.
Sorry for the long post as I know it's a lot to swallow at once, but I haven't even scratched the surface yet. For far more in depth info about airsoft guns, check out ArniesAirsoft.co.uk. It's the best airsoft forum around, IMHO. I have dealt with several retailers and can happily recommend
http://pointact.com/ which is a wholesaler and sells mostly Chinese clones at very reasonable prices and has
exceedingly good customer service in my experience, but has a $100 minimum order, and
http://www.airsoftpost.com/ is just a normal retailer but has good prices and a good selection of both Chinese clones and name brand guns, as well as a very large selection of accessories.
I highly recommend getting into airsoft. Airsoft guns could serve your purpose of target practice in your basement, but they go so far beyond that. Once your back heals up, I would suggest finding a club to go play airsoft with. It is incredibly fun, offers lots of good exercise, and it's pretty cheap to get into as well. Figure a couple hundred bucks for an AEG and some mags, maybe a cheap tactical vest at your local surplus store, some decent boots, GOOD protective eyewear, several thousand BBs(only a few bucks) and you're good to go. It could also be a useful training tool in it's own right as you are shooting at real people who are shooting back at you, and that type of training is hard to come by.
Be warned though, airsoft is a slippery slope. Start cheap and the next thing you know you're ordering yet another AEG because you "just had to have it", another new set of camo BDUs because the scenario game you want to play requires it, a new pistol sidearm "just in case", and before you know it you've got dozens of the bloody things and more gear than you'll ever need and your carpet will be forever embedded with hundreds of BBs. Nobody can resist firing off a few shots here and there at random targets in the house.
Airsoft. Go for it.
