What Caliber? The 7.62x39 needs only to file down the mag catch until a hi-cap mag locks in tight. The .223 is a pain as you must modify .223 AK mags to fit. I understand you can modify the gun, but it requires reworking the front trunnion. The .308 only has American made 20-round mags if you want anything other than the standard.
Depending on the caliber and date of manufacture you may or may not need a bullet guide. My rifle (7.62x39) is of late September manufacture and has a flat trunnion and needed no bullet guide. I've put 30 rounds through it w/ out any issues.
To gain 922r compliance you will need to replace 4 parts and only add American made parts. Any AK stock or pistol grip will work. You are stuck w/ the Saiga fore end unless you are willing to press off the FSB and GB. Typically people replace the hammer trigger and disconnecter (FCG) w/ a Tapco G2 or RSA adjustable and than use a US made stock and PG of their choice. I used the Tapco G2 FCG, Tapco T6 stock and CAA ergo PG on my conversion. I got all of my parts from On Point Firearms (http://www.onpointfirearms.com). They had the best prices on the 'net, shipping was reasonable and fast.
Hope this helps.