I had custom springs made at
http://www.eatonsprings.com/They also had all the right attaching stuff, like spring pins, bushings, U-bolts, and shackles.
The springs I had made were for my 52 1 ton, but the rears I had made 2.5" wide instead of the stock 2". The fronts I had made with 2" of lift, to fit a newer front axle with more drop and still sit stock height.
If you want that much lift to fit bigger tires I suppose you could use essentilay stock front springs. But the rears will need a similar amount of lift built into them. Please don't be tempted to use "lift blocks" in the rear.
I am pretty sure Eaton Detroit Spring can do what you are asking.
One thing though, if you do switch to four wheel drive, the difference in the stock drop center front axle, and the Rockwell square tube may be more lift that you want. Lets say that your stock axle has about 3" drop from wheel centerline to spring pad, the Rockwell has about 4" tube, plus a cast spring pad on top of that. So, you go from a spring mount location 3" below wheel centerline to one 2.5" over centerline, there is an automatic 5.5" of lift in the front with the stock springs.
So, you need to finalize your plans and either swap front axles or not before you order springs.
Grigg