Hello all, after reading many of the pages of this thread (and taking up much time I should have been working) I'm starting to narrow down my selection of parts for my own lighting system. Posting this up for feedback for tweaking and refining the final product before I spend any money.

1) Housings: Optronics MR16 driving lights - reason is fairly obvious. Highly recommended and easy to aquire.

2) Bulbs: Philips Energy Advantage bulbs. Point of debate here
a) 2x 20W. 1x 36*flood, 1x 8*spot - probably plenty of light, but would likely need to run both a fair bit of time to get best results.
b) 1x 30W NarrowFlood 24*, 1x 20W 36*flood, or maybe the spot. - run the 30W primary with the 20W for times when I either need more light, or in evening settings when some light is needed but not primary, or when longer battery life needed.
c) 1x 35W NarrowFlood 24*, 1x 20W 36*flood, or maybe the spot. - run the 30W primary with the 20W for times when I either need more light, or in evening settings when some light is needed but not primary, or when longer battery life needed.
d) 2x 30W, one Narrow flood 24*, spot or flood (input welcome).

3) For one of these setups (Max Wattage = 60W for short periods, Avg Wattage ~35W) would I be good to use the following battery:
13.2V 5000mAh NiMH http://batteryspace.com/index.asp?Pa...OD&ProdID=2193
-OR-
12V 4200mAh be enough. http://batteryspace.com/index.asp?Pa...OD&ProdID=2215

Commutes will be short (35-45mins max travel time), but may want to include some night rides of up to an hour or so. I know the general math behind Wattage/Amps/Battery life time, but wanted some feedback all the same. I'm leaning to the bigger battery. While it is $15 more, and will reduce my bulb life, at a max of 2 hours a day, even if I get only 20% of the advertised life out of the bulb I'll have over a year's worth of commuting life on them.