Surefire m3 head with Lumensfactory Drop in

Hey all, I am trying to find the right drop in for my m961 SF, it has an m3 head on it, and i have been doing research and have come to the conclusion that the d36 sized dropin should fit. So i guess my main questions are:
-will this one for sure fit?
-are they any problems I should consider when doing this?
-and is this a good quality bright drop in?
it says rated at 900 lumens, and this is exactly what I want. I live in a wooded area and the brighter the better! will I be making a solid purchase?

Link: http://www.lumensfactory.com/online_shop_product.php?id=250&cid=3&sid=8&page=1

Pete,

The LF D36 should fit just make certain you keep the foam suspension ring from the original drop-in. If you want greater output look up Nailbender's drop-ins. He makes top of the line gear that would work well for your needs. He has a sales thread in the modified lights for sale forum.