I think the Koni shocks are the best value available but the rears require some mods before you can install them. The fronts should bolt on.

Rear springs are a compromise of course. A matched pair of Super Stock springs is a cost effective way to go but they are heavy and require different front hangers. You might be better off these days with a leaf spring designed for handling.

I haven't spent any time on rear springs in a few years. These days I'd probably start with the Hotchkis springs and go from there. Maybe try a set of split mono leafs from Calvert or take a look at the fiberglass springs that some circle track guys run.