T-8 bulbs can put out the same amount of light as the T-12 bulbs, and take less power to run. T5 bulbs are even better. I have a set of three 2-bulb T-5 lights over my shop workbench and they put out a tremendous amount of light. They aren't cheap, though, as the T-5 is still sort of new, but the prices are steadily coming down.
If putting something up now, I'd opt for something with T-5 bulbs. While there's a confusing array of light 'colors', i.e., 'soft white', 'cool white', etc., there's no standard with the naming. I'd look for something that's putting out light in the 5500-6500 Deg-K range (that's degree Kelvin, one of the more 'standard' standards, but not all manufacturers use that). 6500*K is starting to get towards the blue side of the spectrum, but some people like that. Many big-box hardware establishments will have little light boxes demonstrating the different colors. You can look in them, and see what suits you best. 3500*K, to me, makes everything look a bit jaundiced. I think that's in the 'soft white' range.
Gene Beaird,
Pearland, Texas