i think i saw on facespace that diamond is offering builder housings now, not sure on cost but another option.
if you are broke, id stick with the IFS and save money for a diamond and links. leaves are for trees. you will have to wait longer, but trust me it will be worth it.
If you do spring under, yes, its cast into the diff. But since you will probably do spring over, you'll weld it directly to the top of the casting which can be funIf I'm not mistaken, the waggy44 has the leaf spring perch forged into the casting for the pumpkin.