Lots of good choices. I have a few each of a few styles AK47, AR15/M4, M1 Garand, M1 Carbine, PTR91. And I used to have an M1A.
For plinking at 100 yds you probably do not want the full size cartridges like the Garand in .30-06 or PTR91 in .308. Fine rifles but hard kicking, much more expensive ammo and less easily accessorized (M1A is easier much more expensive than others). I love them but may not be best for your use.
The AK47 is a very simple rifle, but it is not as easy to accessorize and the ergonomics are kind of a compromise. You can put a dress and jewelry on it, but there is still a hairy old Ivan underneath. Don't get an AK for accessory fun. Get it for rugged simplicity. The AK74 is said to be more accurate than the AK47, will have less recoil since it shoot a cartridge similar in ballistics to the .223, and at times the bulk 5.45x39 ammo is slightly cheaper than the older 7.62x39.
Personally I think the AR15 is the best use of the $1,200. Great ergonomics and designed to be modular. If you want something a little more unique get the 6.8 SPC II chambering. It is a FUN rifle to shoot. You can keep it simple and easily shoot with iron sights to 100 yds. We like to shoot clay pigeons set into the hillside at 50 - 100 yds. Or you can add a red dot sight for easier aiming, and get a more customized buttstock and pistol grip. I have some M4 style rifles and am now building one as an A4: 20" barrel, flat top, carry handle iron sight, fixed A2 buttstock to use for CMP target matches. Endless possibilities for upgrades and accessories. Or instead of wimpy, girlie chamberings like .223, 5.56 or 6.8 SPC, you can get an AR in a manly chambering like .458 SOCOM or .50 Beowulf. Expensive ammo but man I bet they are fun within 100 yrds!
For plinking at 100 yds you probably do not want the full size cartridges like the Garand in .30-06 or PTR91 in .308. Fine rifles but hard kicking, much more expensive ammo and less easily accessorized (M1A is easier much more expensive than others). I love them but may not be best for your use.
The AK47 is a very simple rifle, but it is not as easy to accessorize and the ergonomics are kind of a compromise. You can put a dress and jewelry on it, but there is still a hairy old Ivan underneath. Don't get an AK for accessory fun. Get it for rugged simplicity. The AK74 is said to be more accurate than the AK47, will have less recoil since it shoot a cartridge similar in ballistics to the .223, and at times the bulk 5.45x39 ammo is slightly cheaper than the older 7.62x39.
Personally I think the AR15 is the best use of the $1,200. Great ergonomics and designed to be modular. If you want something a little more unique get the 6.8 SPC II chambering. It is a FUN rifle to shoot. You can keep it simple and easily shoot with iron sights to 100 yds. We like to shoot clay pigeons set into the hillside at 50 - 100 yds. Or you can add a red dot sight for easier aiming, and get a more customized buttstock and pistol grip. I have some M4 style rifles and am now building one as an A4: 20" barrel, flat top, carry handle iron sight, fixed A2 buttstock to use for CMP target matches. Endless possibilities for upgrades and accessories. Or instead of wimpy, girlie chamberings like .223, 5.56 or 6.8 SPC, you can get an AR in a manly chambering like .458 SOCOM or .50 Beowulf. Expensive ammo but man I bet they are fun within 100 yrds!