in my opinion (others may chime in as well) you need to do both front and rear since on a big bolt, most if your braking happens at the rear axle as opposed to a car or light duty truck where most braking is done at the front axle.
That said, 55 and earlier have the 5/10 lug setup, where in 56, they went to the 6 lug pattern. I may be beneficial if you are making them, to have an option of bolt pattern.
While i agree with you 100% offering a rear disk kit first would seem... strange to most. One step at a time, first front and if that works well then rear. When the time comes ill be collecting information on rear axles and differences between them so everyone can benefit from it.
My idea for the front would have included all designs if possible (1.5/2ton) with different lug patterns, I would like to be able to help everyone out with their project as much as possible since these trucks are so neglected in the upgrade/ parts department.
