[dsraven]

check the pedals from a trailblazer or envoy. I can get a pic for you if interested. there is a big panel that bolts to the firewall and houses the pedals on the inside, along with the accel pedal and drive by wire stuff, then on the outside there is a brake booster and master cylinder. the panel is recessed outward into the engine bay slightly so maybe a bit more room for the feet. if you got the whole floor and partial firewall you would have an instant floor with a bump for the trans and also a console, cable operated shifter and park brake in the middle the steering column is for a rack and pinion behind the axle so that may not work unless that is your plan. could be modified though.
if going diesel at some point make sure to have a good stout front end and a modifiable spring set.
just a thought. there are lots of those trailblazers kicking around so would possibly be cheap. the engine is offset to the pass side slightly so factor that in if proceeding down that road. there are a few guys doing trailblazer frame swaps but track width is too wide for the AD trucks I think.