Sorry for the late reply, you probably have it installed already, but if anyone else is curious. I used the standard weight spring that was on it. Install is very simple, the trigger itself drops right in, just a matter of pulling the old one out, aligning and sliding the pins in. You will need to grind down the safety stops to allow the selector to move to the binary mode. That was probably the "hardest" part.

I did pick up one of the slide fire recoil enhancers and the gun is running better. I noticed it ran through better through the can, but didn't want to $7/box subsonic ammo through it all day. I still want to polish the guide rails on it and I sent it off to be cerakoted last week. I'll update once it's back, but I've ran about 4k round through it since the trigger and it's still just as much fun.