Congratulations of your new job!
I really like the Timney AR-15 trigger. The head of Timney, John Vehr, is an AR-15 fan and made sure it came out right. It's hard to shoot any rifle well without a good trigger.
Magazines are definitely at the top of the list. I have a bunch of different ones, in various sizes, because 20-round (or smaller) mags work better when shooting off a bench when working up loads, since they're usually shorter than the pistol grip. But higher-capacity magazines can also double as field rests when hunting, because they're longer than the grip. I've shot a bunch of varmints from prairie dogs up from prone using a 30-round magazine as an impromptu rest.
Brownells offers some good mounts, especially under their own name. Frank Brownell also really likes AR's!
