First off, great gift for your wife!
I put a Camaro clip under my frame, it was very straight forward. There are different ways of doing the Camaro clip, I did the lapping method where you leave the clip intact and weld it to the bottom of the truck frame.(simple and drops the ride height about 5 inches) Others have cut the camaro clip and grafted it on to the truck frame using a butt joint connection, the end result looks alot cleaner and like it came from the factory(if your good...) The graft option is more labor intensive and
I think it doenst sit the frame as low as with the previous method I mentioned.
As for the jag rear, it seems really cool, I have one that I was gona put in my 59 but it seemed like a lot of work and I didnt really know how to attack it. I wanted to mount the rear in the cage, but for these trucks, the frame rails are too narrow and you really need to take them out of the cage and mount the diff on a crossmember. I ended up going with the 4 link instead. It really depends on your fab skills. Theres a lot of info on how to mount these rear ends ex:
http://www.jalopyjournal.com/forum/s...t=77729&page=2 (just one quick search) Hope that helped