Rear will be done with the leafs from the same F250 and 5 inch taper blocks.If i dont like the angle of the truck ill probally try to get a set of 2.5 to stack.
If you are planning to stack 5" blocks with 2.5" blocks, I would go another route. That is alot of block lift. You could consider an add a leaf with the 5" block. This setup would be less likely to fail or cause excessive wheel hop.
they make spacers for the airbags now so you can still use them on lifted trucks. They come in 1 inch increments and lock together. Nice wheels i almost went with those when i cracked my weld racing wheels.