Opinions needed ECE Drop 2/4 or 4/6

[72tutone]

Im in the market for an ECE kit. Im debating on whether to do a 2.5 spindle up front with a and 4" coil drop in the rear or a 4/6

Here is a pic of my rear. Sorry I dont have the front as the entire front clip is off the truck.
This is how the truck sits now. To my knowledge and im the 3rd owner after my dad handed it down, this hasnt been lowered at all. My guess is age old sagging as the truck sits somewhat level across it.

Tires are 235/75/15 with 6.5 rally's.
Anyone running the same size tired and the listed drops above? I have done several searches and cant really make up my mind.