AK's are easy to build, we have done them on flats before.
Parts kits are really cheap as well, you could build one for 100 dollars or so if you wanted and they are quality firearms. Major reason I bought the Galil (though that is a more expensive option) was that it it uses AK47 gas piston design.
I prefer milled receiver AK's but again that is more expensive and that is because they feel a bit more solid and less recoil.