The Tec 40 will be my first hotwire. I'm first going to use an XPR103 from Radio Shack. It's a xenon 3cell 0.8a bulb that some others have mentioned holds up well to 4 nimh. But I will be ordering some KPR139s(3.85v,1.32a krypton), KPR130s(3.85v, 1.2a krypton), and HPR44s(4v, 1a halogen). If the KPR139 doesn't melt the reflector, it will give Maglite 6cell performance from a rather small, tough, and inexpensive light, minus the runtime of course.