Hi Guys
Hope you don't mind throwing some info out to you! I work for an electrical outfit and do lighting layouts for commerical customers.
I am completeing my garage now and it is not heated yet (future), I reccomend getting T8 fixtures (1 1/4" tube) w/ electronic ballasts and reflectures, they are instant start down to 0 degrees with no flickering. If you decide you can have 2 ballasts installed and switch how many lamps you want lit per circuit/switch.
There is a new fixture out with T5 lamps but the input on how they are with cold start is not definate yet, mixed response. T12 lamps (1 1/2" tube) cannot be manufactured after July 2005 because of the amout of mercury and phorphous in them so when supplies are getting low it is expected that these costs will go up til supplies are exhausted, they do not handle cold very well.
Metal halide gives very good light and they have a pulse start fixture now that uses less power with the same lumen output from a lesser wattage bulb. Mostly used in high bay applications as they mostly downcast the light.
Recessed fixtures can be fitted with compact flourescents that have a reflector and these are 20 watts total but give off the output of a 100 watt bulb, downside they cannot be on a dimmer circuit. They are great for track lighting too.
Myself I'm going to install T8 fixtures with a reflector giving 10% uplight for fill off the ceiling. They can be supplied with out up lighting and then boxed in to fit the look you might want.
Sorry for babbling on.
Chuck