DO NOT sandblast/media blast inside the cab. No matter what you do, you can't get it all out. Wire wheel does not "drive in rust". You can't "drive in" rust. Just do a good job and use Rustoleum Automotive Rust Reformer. (spray can). It is made for a situation like yours. The can says just remove loose rust and scale. You will be doing much more than that. There are other "encapsulator"/reformer/converter products. Use whatever you like. The wire wheel is the answer for a floor.
Instructions
