James, I run a simple SureFire G2 in a VTAC mount on my BCM. My rifle has a traditional handguard so I was limited on my mounting options, but I really like the set up.

I only use USGI mags upfit with MagPul followers and Ranger Plates or Mag Assists. I never warmed up to plastic magazine in an AR (especially after the Orlite Craze of 10-12 years ago). However, Pmags are universally praised. If you're running PMags you should be fine.

I recently gave away some USGI 30rd's that I had used since the late 1980's. Those mags had new followers, springs, and base plates but still worked 100%.

The new "black teflon" USGI (from D&H or similar) are my mag body of choice. Add a chrome silicon spring, MagPul follower, and MagPul Ranger Base Plate and they will run forever.