Ummm...
Since you already got the stuff this may not help BUT
Ive assembled 5 lowers in the last 3 years and all the small parts came from RRA and Brownells
even durring the One Big @$$ Mistake America scare at election I got them quickly...
HOWEVER I had to order everything piece meal not as a kit... No big deal really
I always order enough stuff to build two when I order
I now have one heck of a small parts kit.
As to triggers
Ive tried the Two stage Bushy IIRC and Im not a fan, its kinda like a Glock trigger to me easy takeup and it stacks at the end just to make SURE that you really want to fire the round.
Ive got three and have built a couple more for others.
CMMGs trigger is the one in my lower the 450 is on..... its not a bad trigger but the adjustments dont take all the take up or overtravel out.. so its pullllllllllllllllllll about 1/8 to 3/16 I would guess then presss about 2.5 ish lbs and then when it releases its got about 1/8 overtravel then deal with a 1/4" reset and do it again! Its a serviceable trigger but nothing special
Ive done two accuracy speaks triggers ..... Very Nice they also have a Flat faced trigger with no casting mark on the face..... which makes it feel like a TRIGGER
(I sand the face of all mine to get rid of that casting mark, drives me NUTTS) I wont say 0 takeup or over travel but its very little, and reset isnt bad at all. One of those triggers is on a Swat Snipers 6.8 SPC that he uses for backup or entry when needed
Ive done my 6.8 with a JP trigger that is just SWEET no over travel and no takeup breaks a little less than 2.5 I would guess but reset is minimal.
I have never taken the time to put my scale on those triggers but I have a pretty good booger finger scale.
My other Ar is a Gunsmith hack job that needs to be replaced. If I knew then What I know now I mighta punched that guy that called himself a GS.
Larry