This picture worries me a bit...
Looking at your rear shackle angle, it seems your spring hangers are too close together. See how it's already angled back ? Once you add the weight on to the suspension of the truck and bed, it's going to angle back even further. The leaf springs will "get longer" when they flatten out under load. Your shackle angle is going to be bound or near bound up.
Just thought I'd add that to give you something to ponder before you get too far into the build. I'd hate to see you get the thing all done up pretty then have to move and redrill a bunch of holes to change the rear hanger angle.