I have never ran either of them but for my truck I have narrowed it down to the F-150's or Bronco II/Ranger rears for the rear of my truck, The only reason I do not want to run the Chevy's is because they are so long, I am just going to avoid them for now.
I actually should be getting the Bronco II springs tomorrow, if I get them I will try and mock them up to get a rough Idea on how they will sit so watch my thread in the project build up section. Honestly i think the Chevy springs will flex better but you have to have a long ass shackle to compensate for the compression of that long spring. You can also go for some 52" Chevy springs , but I am not sure what trucks those came in or how well they work.
What ever I run in the rear I will most likely add two or three cut leafs into the pack.