The semi-float would be alright. They are plenty strong and lots of parts and available gear options. If I remember right, the semi float is a little narrower than the full float 3/4 ton version. The full float would be a good choice too, since you have a flatbed and no fenders to worry about. If you wanted to narrow things up a bit, you could find some dually hubs and install them on the full floater. Of course, you'd have do some modifying on the brakes. Some B350 Dodge vans used a wheel with more backspacing, you could use them to narrow things up a bit too.
As far as the front brakes go. There is no definative solution yet. Grigg, myself, and some other members are working on something that will work on the 3/4 and 1 tons. I would definately hang on to the master cyl. and booster, you may be able to do something with it later.
Chris
BTW, I have a 67" full float and a 63" full float. Check out the pictures at
www.photobucket.com/whitedog76pics
