Surefire M4 LED conversion?

Searched but came up with nothing recent, have a perfectly good M4 laying around and would live to upgrade it to LED. I know Malkoff made a tower, its out of stock. Any other suggestions, want to run with 17670 batts. Thanks.

Lumensfactory makes a tower module for the KT-4 head on your M4, in various tints and single or three speed. highly recommended...

LumensFactory also makes a Turbo head for the M-Series lights.

Surefire
M3, M3T, M4, M6
M2 or P/G/Z Series lights with M Adaptor Installed

Lumens Factory
Seraph SP-6, SP-9 with M Adaptor Installed

Lamp assemblies for this head are the MN15, MN16, MN20, MN21 and all Lumens Factory assemblies that are compatible such as the M3T-LED, HO-M3T, IMR-M6, etc.

This head is NOT designed to use the smaller MN10, MN11 lamps and other lamps that are designed to replace them such as the M3-LED, HO-M3, etc.

Thanks folks, I found those but they have spotty reviews. Any firsthand experience with the LF heads?

I had a LF turbo head on one of my M6 lights for awhile and it was a pretty nice setup. Not bad for the price and other than the difference in finish I was pretty happy with it. Ended up getting a Malkoff drop in and sold the LF head. There are other options for a drop in. Tana makes a very interesting new one. A design that is well thought out but they are not cheap. However when it comes to quality it is rare to find that for cheap. It's gotten great reviews and he makes them on a limited basis. I'd recommend an XML size die in a KT4 head though. It's been my experience that XPG size tends to have excellent throw but not the best spill in that diameter reflector.