You can probably find out lots of info over on one of the AK forums. The PolyTech .223 mags will probably work fine and I'm sure one of these forums will help you out with the info you need...
The AK Forum
The AK Files
The stocks are somewhat interchangeable with other AK's. This depends on your receiver type. A slant cut receiver is not as compatible as are the straight cut receivers. It also depends on what type material you want for your stock, wood or synthetic. A place called Iron Wood Designs
makes wood stocks for all sorts of AK's out of many different types of wood. Check them out.