So in reading around on AR15.com and a handful of other places, it seems as though for what I'm looking for I'm just as well off buying a whole gun as opposed to building one. I'm not hunting anything and really only intend on having it as part of a collection as well as target shooting. Would I be best off just getting something like an RRA Varminet or something with a longer barrel at least? I like the semi-auto rifle idea, but I suppose for distance target shooting I could go with a bolt action of some sort too... Never really considered that. Time to buy two guns I guess.