If you're just going to throw a sporter stock on it and use the iron sights, either a mosin or mauser will work, as I've said. A refurb M91/30 is $90 around here and most of them have great bores and will shoot sub 2" groups at 100 yards. A NIB M48 or an arsenal prepared 24/47 yugo will shoot just as well. Most of them are in the $200+ range, but you can find M24/47's in the $180 range if you look around. They usually have nice bright bores and also shoot really well.
Either way, if you're sticking with the iron sights, consider getting a set of Mojo sights. They're leaps and bounds ahead of the native sights on any of them, both for hunting and target shooting.
As for ammo, since you said you want to use it for hunting, the cheap surplus that's available for both of them is less than useful since it's FMJ and sometimes steel core. Domestic production 8mm is loaded to about 30-30 levels and works fine if you're shooting at sub-150 yards. Prvi Partizan is cheaper and a little better, but not much. BVAC makes some 175-grain loads that are full power and should be good for out to 400 yards +. With a good gun and the right scope.
I haven't shot much new-production 7.62x54R, but the winchester white-box stuff it supposed to be pretty good. Again, Prvi Partizan makes better loads that are relatively cheap and reloadable.
If you go with the mosin, mojo sights, and cheap sporter stock, you're still going to be in it $200+ and will still have to scrounge around a little for ammo.
For plinking etc, either one is great. 1950's era Yugo 8mm can be had for about $0.30 per round. Soviet bloc surplus 7.62x54r can be had for about $0.25, but it's steel core so some ranges won't let you shoot it.
For target shooting, the 80's Yugo M76 sniper ammo is hard to beat. Very accurate.
If you want to be able to sell the gun later, don't bother with either of them. They'll be worth more untouched than modified. Once you decide to do any non-reversible mods on them, they lose almost all of their value.
I do have to disagree w/ Ohio Gun Guy on one point. Sorta. Most of the refurb Mosins and M24/47s have very good bores and will shoot close to MOA. BUT that's if you're shooting bullets that fit the bore. The winchester production 7.62x54r that I've seen has been using .308 bullets when they should be using at least .311 since the grooves on most mosins are in the .311-313 range, even new. Prvi is loaded w/ .311 slugs and from what I've heard shoots great in mosins. The surplus available isn't anywhere sub-moa ammo, but is acceptable. Bore size is always the biggest variable w/ surplus rifles. I've got an Argentine M1909 that was originally chambered in 7.65x53 that was reamed out to 30-06, but retained the .312 bore. It doesn't shoot 150 grain spitzers worth a darn. I put some 180 grain round nose bullets in it and it shoots very, very well with them.
Matt