Hi Peter. I'm one of the Armalite guys around here. Don't listen to these guys. You can find parts for AR-10's fairly easy as long as you stay on top of what you're looking for. Go buy yourself an AR-10 carbine to start with. As you learn about the platform, you'll become comfortable enough to build one after a while. Either an Ar-10, or an AR308 patterned rifle. Though I'd stick with the Armalite style. I mean, once you're driving a Lincoln.....you don't wanna change over to a '73 chevette. <lmao>
Oh, and get ready to laugh as these guys start to lay into me. No worry. I can take it. I'm used to it. <lmao> They're all just jealous.