Big surprise, I employ the low-tech old-school way. Some outfit named Tac-Star or something similar made this about 10 yrs ago. Pressure switch is difficult to secure and even the softest cases have cost me more than a few sets of expensive batteries.
I personally prefer tail-cap G2s and similar flashlights instead of the TLR-series. The TLR's tab makes it too easy to ND the light. Indeed a friend had his TLR-1 accidentally activate while cased away and drain the battery.
I'd suggest using the tlr series lights but getting the remote tape switch for it that replaces the standard switch battery cap. When I home next I'll post a couple pics
I have a rail on mine and this light on the left hand side (off set weight helps reduce the already mild up and right muzzle rise). I have a G2 LED and this light is seriously better (brighter, whiter light) and has a strobe mode. I'd never buy another G2 again....
I have the MagPul fore end with a piece of 2 inch or so rail mounted with a VLTOR ring and a old Surefire 6P on a Bushmaster Patrolman Carbine. Works fine. Just hit the rear button with the left thumb. Cheap and effective without all that quadrail fore end jazz. Red Dot is an Aimpoint 2MOA M3 on a Larue mount with Larue fixed BUIS. Like to keep it light and simple.