My last spring purchase a few months back was B-body XHD springs, Espo beat everyone's price to my door.
Prior spring purchase to that was a set of the MP 002/003 for a Duster, which were least expensive from Summit.
Get some rear bushings while you're at it, and some angle shims for the saddles in case you need to deal with pinion angle.
If you go with a stock setup and get wheel hop, you can just fab up some clamps for the front sections.
If you go with the SS deal, remember they need longer-travel rear shocks.

I just want to add that you should get the best the 1st time and sqweeze it into the budget!! I have Cal Trac split monos & viking shocks. When I go to the track a few times a year I want the performance and adjustability in the rear suspension for a good hook or a greasy track.

Let 'er RIP!