For the U.S. parts you can go with either of the two most common. The RSA for an adjustable Fire Control Group or the TAPCO which is what I have installed in most of my AK rifles. 3 parts
The ACE folder comes in two mounting types if I remember right (I don't have one but did look at them before, I do have an ACE stock on one of my AR's and I like the quality). One of the mounting types is an adapter block that goes on with the regular stock tang, this adds extra length to the stock. The second type of mount you have to cut the tang off. This should be easy but it is more or less a permanent modification. People have stated here that the stock locks up tight, they do look good to me but your preference may vary. 1 compliance part
A U.S. pistol grip 1 part
The Romanian and East German stocks go on in minutes. I have owned 3 of these and liked them until I messed up my shoulder. I had to sell them all off. They are in stock with several dealers currently but have gone way up in price. Doesn't count as a compliance part. 0
To get your handguards off. Field strip the rifle removing the receiver cover, recoil spring and bolt carrier/piston assembly, lift the lever on the right side of the sight base and remove the top handguard. At the front of the lower handguard you will see a lever, lift it, push the lower handguard forward and pull it out of the receiver. To remove the wood from the top handguard, use a vise at the back end or an adjustable wrench and turn the gas tube/or wood 180 degrees, you can now pull them apart. If you replace the handguards with a U.S. set it only counts as 1 compliance part total.
Linx310's site with directions:
www.gunsnet.net/Linx310/index.shtml