ARs are like car tires… while there are dozens of “names”, most of the major components are made by one of only a few companies…
Each person has their own feelings on some stuff, some guys dont like brand X just because it is made in a state they dont like, or has a logo that is not cool. So, if you stick with a list of about a half dozen or so names, you will be fine. Short list of places that make complete rifles, not all inclusive:
Colt
Rock River Arms
Stag/CMT
Bushmaster
DPMS
Armalite
Smith & Wesson
Or you can have a dealer here build you one, and end up with a quality lower with a different name… POF, Mega Machine, etc – and you will have a damn nice gun that way.
Given what you are asking, I would suggest talking to a dealer about a lower receiver assembly from any of the above – each of them has their druthers really, and then take a look at what they offer in the way of uppers set up for what you are looking to do. Some of the folks do not deal in lower receivers, due to the license required, but turn out great uppers… and the two just snap together with two pins.
Hit the dealer forums on here… go to there web sites and look around. JTac, G&R, ADCO, Bravo Company and others… each person has their own style, but all of them use good parts and can build a good gun – at this point, it is pretty much about finding someone that you like talking to and puts together what appeals to you.
I am sure that within the passing of one sun, there will be someone along that competes in the style of matches you are looking at… someone more qualified to help than me, bullets coming out the pointy end every time I pull the trigger is all it takes to make me happy. I will suggest a starting point of a 16" barrel and mid-length gas system… that is a great choice for anything within a few football fields.
eta: see, while I was typing, they were already showing up!