I am looking at some different AR setups... and I want two major types. I want a good distance gun in a SPR config, but I also want whatever you want to call a 14.5 gun setup. Does anyone run one lower with two uppers? Is that just a bad idea? I am thinking of doing the SPR first most likely as a complete rifle, and just buy a short upper to stick on it. That way the SPR everything is fit well. That or I may start building a rifle super cheap(The 14.5) a part at a time then just end up with two full rifles.