Rear setup is similar to hemidog above. 3/4 relocation kit, American Muscle shackles, B body width hub to hub, with Wilwood 4 piston rears. I ended up having a custom length and arch 6 leaf spring setup made at a local spring shop, instead of using the A body part, but you can get there either way. I had DTS build my rear end assembly complete around a Strange S60 case, Eaton Posi-Lok, Richmond gears, and Strange S/T axles with green bearings, and I highly recommend going this hub-to-hub route with a shop that stands behind their work. The only thing I left loose was the perches so I could weld them up in position once I had the stance and pinion angle setup.
My latest wheels are 17 x 8 front with 4.25" backspace and 17 x 9.5 rear with 5.5 backspace (to inside of rim bead). I have 1/4" spacers in the rear to get a little more leaf spring clearance as this wheel measures to inside of rim bead. (Note - e-body rear frame rails tolerances are notoriously askew, placing your rear perches +/- 1/4" at the rear bushings if you're lucky.) Rubber is 245/45-17 front, and 275/40-17 rear. In back, I have room for a 1/2" more rim (outside), and 3/4" more tire.
As hemidog describes, e-brake setup on a rear disc conversion is McGyver territory. You have to be ready to do some fabrications, chase a lot of nitsh&$t parts, etc. The Wilwood setup with a small drum brake in the rotor hat for e-brake (really a PARKING brake) uses Ford Explorer cable e-brake parts, and several hot rod parts suppliers carry them.