Is this based on having actually held one in a gunstore? Maybe try taking one to a range (after getting the correct PAL and paperwork when you're old enough) and actually putting some rounds through it before pretending to understand what you're talking about, because it's clear that you're so far out of your lane that you're going to need an on ramp to get back where you belong.
As far as the Spikes LE uppers go, they seemed to be a great deal, Wylde chamber, chrome lined, FA BCG, 1/2x28 threaded and buffer for a very reasonable price.