From what I understand, the standard FA BCG’s work just fine and you don’t need to “enhance” anything.
The important stuff is a MP tested and shot peened bolt, extractor with proper insert and spring, and a carrier with proper key screw staking. The LMT BCG’s are good to go in all those respects.
i have a back-up BCG and spare bolt back-ordered through lmt, their sales rep emailed me last week concerning my order, said scheduled shipping is 12-29-08, i beleive there is some around if someone looks enough.
Check frequently at G&R, or at BCM, for BCG’s that come in and sell out quickly. You never know, you may just hit it right. BCM or LMT FA BCG’s would be my first 2 choices. YMMV.