I would look at joining some of the gun builder websites. weaponsguild.com is very good. They helped me with a couple of HK builds, and some of the special tools to get them together. Of course, AR15.com is pretty good, if you can sift through the attitude problems and general garbage. akbuilder.com is another that I can recommend.

If you are looking to build AR platforms, I would suggest you have a look at the Magpul AR wrench, it has to be the best I have seen or used. They also have a tool I recently picked up, the BEV Block. This works far better than the clamshell type of fixture I was using.

When it comes to AK tools, I have taken some ideas from AK builder, and built my own rivet fixture, and I even used an old microwave oven transformer to build a spot welder for the AK rails. Your best bet is to do some looking around, and see what you think will work.

Always here to help a fellow Veteran. Semper Fi.