Goober,
What I've seen a lot of guys do is they keep the brake booster. They weld a bar in underneath the drivers seat to the frame, the whole brake setup is turned around backwards, then they take the brake pedal, turn it upside down and put it through the floor. They have a bar underneath that they have support the pedal, now they weld a rod to the bottom side of the pedal arm or what used to be the top side ( a piece of flat bar). They drill a hole in that and bring an adjustible rod back, now when they press on the brake pedal it presses on the master cylinder which is mounted underneath the floor board of the drivers seat. The master cylinder comes up through the floor a little, you can always put a cover over it. That's the way I've seen them do it.

Vegas