I did white walls, white ceiling, and light gray epoxy floor coating. For lighting I used the lowest cost recess 2 ft by 4 ft florescent fixture designed for a tiled drop ceiling - troffer I beleive is the name - and recessed those into the ceiling between the rafters with 1 drywall screw in each corner. Add 4 T8 natural day light bulbs. In my 25 by 30 garage I have 6 of these units in the ceiling - plus under cabinet task lights over the workbenches - and 2 standard ceilng retractables with 150 watt rough service bulbs between the 3 car bays
http://www.lowes.com/lowes/lkn?actio...507&lpage=none
You can get the fixtures from a big box store at 40.00 - or on sale for 25.00. You can also buy them from surplus outlets or from someone who's taking a bunch out of a building. Ceiling retractables from Harbor Freight. Box of T8 bulbs are 35.00 avg.