I am in the same situation. I found some 4x2 T8 4 bulb troffers on CL. the guy wants $15 each for them with bulbs and has a bunch so I think I am going to try to get some this weekend. I tried loading the Lithonia lighting program from their website but I can't get it to work. I have about 900 sq feet in my garage and I am thinking about 8 fixtures would be plenty but I am just guessing. My ceiling is 9.5' and white.

The ones I found are Metalux GR8 series, new in the box with lights for $40 each. Not as good a deal as I had hoped. They also say they are "UNV=Universal Voltage 120-277" so I'm not positive they will work for me? Will these work on standard 120 electric at my house?
I went to the cooperlighting website and found the light I was looking at and clicked on the Calculate link, and it open up a cool little program to calculate how many lighs I would need.
They will work for 120-277V, just connect the supply voltage & they will work.
At $40 bucks each I would look elsewhere.
Dipper, did you or your brother buy them used? Are your brother's surface mounted or recessed in the ceiling? The ones I am looking at are new in the box, with lights.
Thanks