What is a better JP single stage trigger setup. The drop in modular unit or their standard single stage trigger kit?
Does the trigger kit that is non-modular require any fitting or is it basicaly a drop-in?

JP single stage trigger setup. This trigger is not drop in. it comes with a dvd for install instructions.  Not hard, just have an extra disco on hand.

The modular kit is okay (still better than anything else out there), but the trigger kit (a.k.a. Fire Control System), is the heat.

I put it and their hammer in all my rifles (if I could put it into my duty M-4 I would) and it doesn't take too long, especially if you already know where which spring does and how to get everything in there with the disconnector.  My first install was on a Colt, so it had the stupid sear block in there.  POS!

That being said, when you're installing it, a couple of drops of Loc-Tite (the really light one) on the sear adjustment screws will make your life super easy.  However I did shoot the first one for 50k rounds before there was a minor issue with the release screw.  Quick adjustment (and I figured it was about time to change the springs anyways) and back in business.

Rich