Thanks guys! To answer my definition of a complete upper, I'm talking without the BCG and CH. For some reason I thought all of Aero's uppers were tested it but re-viewing their catalog I was wrong. The reason I asked about the Spike's BCG is that I read the machining quality on the PSA BCGs were rough until you used them.
Anywho, reading different build guides led me to never skimping out on the Barrel or the BCG and many recommend the testing on both. Since BCG is the heart of these, I wanted to know if I could trust Spike's or PSA's BCG to allow to go bang without frequent jams or going into single shot mode. As for the $300, this is more of a target area for my upper, not necessarily a limit. I'm not planning any ammo dumps, just light target practice gun, possibly upgraded down the road.
On a separate note I have owned an AR before, it was an Essential Arms J15 pre-ban. It had a lot of feed problems, but was a beautiful rifle.