You might want to consider a Ford twin I-beam IFS. Here's the one under my '32 pickup which was done with air bags.
And the one under my '29 sedan delivery which was done with quarter elliptical leaf springs.
I've never done one in a Bronco frame so I don't know what special problems you might encounter...but it might be worth a look as long as you are considering all options at this point. I don't know how helpful it might be, but you can click here
for the step by step description, with pictures, of how the sedan delivery suspension was done. I prefer the beams from around '78 and '79 because they look like a traditional forged straight axle. But other years may be used as well.