I happened upon a Modlight 18650 body that I'd like to use for my SBR. The issue is that I'm flashlight ignorant.

Will any SF/Modlight/?? heads and/or tailcaps work, or do I need to look specifically for Modlight components?

TIA!

Any Surefire Scout light tailcap will fit.

Many heads will fit that body, but the Modlite heads are the best I’ve tried so far that will fit that body, but Surefire DF heads also work. I’m pretty sure a Surefire Turbo head will work, but I haven’t tried one of those yet.

Classic SF scout 600 heads will not fit, they have a smaller diameter at the threads.  Modlight copied the SF duel-fuel head thread spec, so you can use the Modlight heads, SF-DF head, and SF-DFT (turbo) head for the 18650/2 cell bodies.

There's also some other odd-ball options out there like Z-Bolt and Weltool, just make sure the head is sized for the SF duel fuel thread diameter and if you plan to ever use two cr123a batteries instead of the 18650, make sure the head is capable of running on the 6v primary batteries as well.

I've continued trying to get educated and think I'm going with a PHLV2 head and a SF tail cap and the TRex mount. Thanks all!