I think the firing line receiver just might be the way to go although it looks like it costs $389, if i am not mistaken. it may save you enough in tools to be worth it however, and the build should be really easy. just screw in the barrel, and assemble. no riveting, no pressing, no drilling, dremeling, etc. the other advantage would be that the receiver counts as one us part, and also eliminates the trunion from eligible parts on the gun, bringing it down to 15. Someone correct me if i'm wrong, but I believe this would make only 4 us parts neccesary, and you already have one. so get a $25 fcg in a group buy, and other than furniture your rifle is complete. I wish you luck in your decision making, and by all means let us all know how it turns out.