batteriy and bulb options for 4D Mag

I have a 4D mag that is stock right now except for the 3D bulb it has in it, and I would like to modify it for more light and longer runtime. This light will eventually end up on a jump bag that will mainly stay in my car so that it is always close at hand.

I would like advice on which battery and bulb combination would be the brightest while still giving me a runtime of about 2 hours. I am looking for a potted bulb for light and either using D size alkaline or AA NiMh's in 3AA to D holders for power. I would not object too much of replacing the lens with a borofloat/UCL and the reflector with an aluminum one, but if it is unnecessary, its less money I need to spend.

I know lithium batteries would have the longest shelf life compared to alkaline and NiMh, but I won't have any problems maintaining/replacing the batteries on a regular basis.

alkaline batts have sucky current capabilities.. but 4 cells.. 4.8V.. the 1183 bulb will get you over 400 lumen if you fix the switch.. 2.6 hrs runtime on 10AH NiMH D cells. about 1/2 the output the 1319 will get you a lot more runtime and with less than 10W output you won't have to replace the reflector.

-awr

When you say "fix the switch", do you mean I would have to install one that can handle more current? I believe my Mag85 has a stock switch, the person I bought it from listed the parts that he had replaced on it but never mentioned the switch. It seems that this would draw less current than the 85, so would it really need a new switch, especially if I would be able to use the stock reflector and lens?

Also, how long would it take for the 10Ah NiMh D batteries to self discharge?