Long Travel kits are not sold based on a lift size, keep it low. I would suggest cut and turned beams, heim radius arms, and 4" coils, or even better, coilovers
I would not go larger than 35's with the Dana 35's, bigger the better though!
Don't move the radiator, you will not gain anything from doing so.
Unless you plan on linking the truck, the stock fuel tank is fine. If you need the clearance, I'd recommend a Bronco fuel tank over a fuel cell. Fuel cells are tough to keep smog legal, and the fuel delivery (pump/filters) are not as reliable as stock.