I love Fenix especially the way they can be interchanged. I can swap out the middle of my L2P and use either one AA or 1 CR123. They make an excellent little folding knife as well.

Leatherface if you are going to upgrade you might want to go hard and get the CR123 cree light(I forget the alpha numeric designation). It is the same size as your L1P and is total throw monster. You can get a CR123 battery on the net for 2 or 3$.