I thought I heard the Magicshine batteries had issues with the waterproofing. I know some people were mounting them in a spare waterbottle with a hole cut in the top.

As for price range, I suppose 100$ would be the max i'd like to go, unless the quality would be staggeringly different. My commute is suburban for the most part, but the roads on the latter part of it are not very well lit. With my current lights, I can't see much, but that's just due to the design on the lights. There are some areas with no street lights or a substantial amount of space between street lights.

The only real difference with the battery types then is runtime? I just thought there was a difference in power level or something too. If the price isn't too crazy, i'll invest in the rechargable 18650's and charger. Either way i'm going rechargable.

I assume I need a fairly decent light, but I can't really be sure since I have nothing to compare it to. I suppose i'll just buy one flashlight and see how that works, then go up from there if need be. The magicshine system is a bit out of my range, though I don't mind springing for it if it would be the better choice.