All good advice above IMHO. I'll add that HS was THE .22 target pistol to compete with back in it's day. I've owned three and they all had nice triggers and excellent accuracy. They were also pretty reliable as long as you kept the mags tuned . ( Very important!) The new versions are noted for ( and personally observed ) being unreliable period. If you want a HS, look for an early hamden/hartford gun. Models differ mainly in sights ,barrels and frame angles. Look for heavy/target barrels and adjustable sights for target work. It is not uncommon to find guns with interchanged parts ( i.e sportking frame with better citation barrel , etc) There is a great colectors book on the subject if you really want to get up on it. Cost is $20 or so but well worth it before you dump $400+ into a good one.
Lastly FWIW, as much as I like the old HS's I'll mention that I just sold my last one off. Why? it's my experience that they tended to need occasional parts, work and/or tweeking to keep them functioning flawlessly as required for any kind of formal target shooting. I also found that magazines, grips ( and competent gunsmiths) etc were getting increasingly hard to find and increasingly expensive. Lastly, unless they were previously modified (drilled and tapped), there was no cheap/easy/ clean way to comfortably mount a dot sight on them. ( Something many target shooters end up with.)
Having said all that, it's MHO that while the older HS pistols are scary accurate and a joy to collect/ shoot. However, I don't believe they are the best bang for the buck for a new target shooter . Something along the lines of a comperably priced Ruger MK II/III target would likely provide a similar (practical)level of accuracy and be much easier/cheaper to upkeep, modify and accessorize.
Not an expert here, just a .22 target pistol collector /shooter passing on some personal experience and thoughts.