I just went to the range again tonight and sent another 400 rounds down range. I seriously need an autoloader of some sort. I also purchased a MOE V Grip and it worked quite well. Full auto or bursts anytime I wanted. I still had a decent amount of FTF; about 1 per magazine. I did have two full drums (50 rnds) go without hitch - thats what drew the audience at the range.
In regards to the trigger, you want model #667S . This is the .154 pins. The larger pins are for the older Colts. I purchased mine at Midwest Gun Works:
Timney AR-15 Small Pin 3 Pound Solid Trigger: MGW
Ordered: 1 Shipped: 1 TIM667S Timney AR-15 Small Pin 3 Pound Solid Trigger $184.23
It looks like they just sold out. I see you can get them here as well:
Timney Triggers AR-15 Competition
Not sure if it is instock there or not.
Make sure you buy this as well; KNS non-rotate trigger pins:
M&P15-22 Non-Rotate Trigger/Hammer Pins (GEN 2 MOD 2) Black
Buy it from there as the pins are different sizes than normal AR15 lowers; the one I linked is made for the S&W M&P15-22.
If you don't buy the KNS pins, you will have to screw the set screws of the Timney into the poly frame - which isn't good as it doesn't hold all that well... then your trigger pins fall out.