You've probably seen this already (but pics are no longer linked by photobucket), but for our last build, we cut down a Chrysler Mini-van middle seat. Got it from the local U-Pull for cheap. We cut off the armrest and the floor mounts and did a few mods to the frame to allow for the seat to bolt down through the floor and frame. The frame and foam was narrowed about 3-1/2" and rewelded and foam glued. The seat bottom can swing up to allow access to the battery, toolbox, small personals tray, and the wiring panel. Since it uses the factory seat spring suspension and foam, it is very comfortable - more so than my fabricated seat in my '27. Minus the upholstery job, we have about $60 in it for the seat, and misc brackets we used. Here are a few pics - I have more detailed pics on how we modified the frame if desired.