I'm using S10 pedals and the stock steering column. I ran the two support rods back to the mounting holes for the steering and one goes right through all the layers. The other is it's own hole.
I got the power brake booster and the pedals for like $25 at a local yard.
This is on an AD truck.
I've got a set from a Nissan as well but I haven't mounted them. They were $20 complete. Slave cyl, master cyl, and mounting holes.
I may eventually extend the pedals a bit but I don't think they are that far off the floor that I'm going to sweat it. Once she's a runner, I'll let you know!!