I think the best for the money are the Zastava guns they are nicer than the Romanian guns but not quite as nice as the Arsenal/Bulgarian. They are kinda between the two in terms of quality.

If you want to trick it out with different handguards, stocks, etc. then look at what is available for whatever you decide to purchase. Milled vs. Stamped, etc. not all parts are interchangeable. That being said you can spend a whole lot of money on an AK and with imported "cheap" ammo it probably won't shoot any better than a WASR 10/63. That has been my experience. The only ones imported after the first ban I've ever seen shoot real good is an SA-93 or the milled Chineese/Norinco guns. Those are usually 1.5MOA guns. Those will shoot. Everything else I've ever shot was less than stellar in the accuracy departments. Price didn't impact that much.

Just stay away from US made parts if you want something to keep and retain value. I think these US made Frankenstein parts guns are hit/miss some are good others junk.