I was at Ikea ith my girlfriend and I noticed they had a "build your own table" section. I was able to get a nice flat, strong table top and a set of legs with built in shelves for around $35. I use a Great Planes building board on top of that. Before that I have used an old glass-top dining table that was nice and flat and some kitchen cabinets that I made an MDF top for. When I get my new garage set up, I plan on building some sort of bench on casters that I can roll to the center of the room and work from all 4 sides. The door works pretty good too; I know people who use them. If you can find a used or damaged one, that'd be great. If not, a plain interior door slab isn't all that expensive.