Hi @xXSteev0Xx,
The first thing I've learned here is how little I know about large frame ARs. Buying a matching/same manufacture upper/lower set saves a lot of head aches, don't always believe the guy behind the counter selling you stuff. While I own a couple large frame ARs I've yet to build one, fortunately there are people here with the knowledge to answer your questions so like you I'll be learning as you go through this build.