Your desire to have an uber-clean chamber isn't bad by any means. It is, however, a product of an archaic cleaning regimen produced by military standards. I was the same way after my EAS from the Corps. I thought all rifles needed to pass a white glove test and anything more than a thin film of CLP meant certain doom.
Years later I have found the opposite to be truthful. The only clean chamber (by military standards) on any of my rifles is from a brand new unfired LMT. Once I get around to using that rifle I won't focus on the chamber, I will focus on a maintenance regimen (lubricate generously, wipe down/bore snake every 1k-2k rounds) that has proven successful for my application.
The reason people argue quality parts against lesser brands is because the price difference isn't tremendous. The beautiful thing about AR's is that even if a guality production rifle is out of the budget, you can allocate the funds over time to build a great rifle.
Take my course rifle for example. There is no way I could afford the rifle brand new. Rather than buying it new I built it over a period of four months.
Vltor MUR upper
DD M4 12" rail
Sabre Defence 1/7 16" middy
LMT Enhanced BCG
LMT complete lower
Addax Phalanx FH
(photo from a Trident Concepts Advanced Carbine Course)
Keep in mind, I can wrap my mind around why you want the feature your Stag rifle has. I'm not saying you are in the wrong for desiring that feature, all I am saying is that through all my training and shooting I have yet to find a legitimate need for focusing on the cleanliness aspect.