Well you could do the fire control group yourself, you can't screw anything up and you will save a few bucks. It took me about a half hour, I had a little trouble getting the shepards crook to stay in place when I was putting the trigger pin in.
The gas piston would be tough getting out without doing any damage to the bolt and you will need a drill press to install the new US gas piston. There is directions on Red Star Arms web site if your interested. You could buy or rent the barrel threading kit and try it on the kit barrel first and if you get it right you could do your barrel. Evryone says it real easy and the guy who rents them gives you his cell number in case you have any problems.
Your best bet is to send it off to someone who builds AK's like Ohio Rapid Fire, InRange, Tromix, they all have web sites. There are other guys out there too but I know those two guys are known for doing good work. I don't think there is anyone local that builds AK's but I could be wrong. If you find someone local let me know my SAR still might be lying in a box in pieces.