Just to put a wrap on this thread I picked up a S&W M&P 15 with magpul flip-up sights. It is a flat top chambered in 5.56 with a 1:8 and I picked up a couple extra 30 round mags from pmag. Ended up at $800 OTD.
I'm pretty happy so far. It is the big brother to my 15-22. My LGS was out of the Colt 6920s but did have several RRAs in stock. He also had a Sig Sauer that I almost went on but I couldn't justify the extra $300.