There are lots of good triggers out there, but my recommendation goes with Giessele. A bit pricy, but worth it in my opinion.
I have BCM BCG's in both of my AR's and am quite happy with them. Slightly more expensive than others maybe, but they properly stake the gas key.
Twist rate will depend on the bullet weight you want to use. If you're sticking with 55gr FMJ, for example, then a 1/9 twist will be fine. If you are using something heavier, perhaps a 1/7 or 1/8 would work better.
Good equipment will never be a substitute for good training.