I've built several AR 15s and the best trigger I've come up with for reliability and overall feel (I have a 24" barreled AR target rifle) was an Anderson Stainless set that I cleaned up and polished with a set of JP Enterprises enhanced reliability springs. Great trigger at consistent 4 lb pull.
Other notes, I picked up a Patriot in 308 a couple years ago to do a 500 yard target rifle. It shot ok but I didn't like the plastic stock so I picked up a Boyd's thumb hole stock and a Harris bi-pod and finally got to shoot it last month when I went to Colorado to visit another YouTuber at 550 yards at a 12x18 steel plate and it was awesome. I didn't like the Bushnell scope I had on it so I picked up up a Nikon P-308 and a set of rings and bases and it made all the difference in the world for me. Loaded up some 168 grain Hornady A-Max bullets. I still need to put in pillars and bed the action but I like the rifle a lot.
I got the rifle for $275 with shipping and transfer, Stock was $145 shipped and the Scope, rings and bases were $325 installed and bore sighted. Just under $750 into a rifle that is the way I want it. The nice part was that I didn't have to pony up that much cash at one time.