Looks great already! :thumbsup:
ESPO is probably your best bet, a set of XHD's with the stock arch should be the ticket.
The factory spring rate wasn't as far off in the back as it was in the front. The XHD's should be ~110 lb/in, most of the road handling springs are set up to be in the 120- 130 lb/in range. Peter Bergman has a set of springs that he sells at Bergman AutoCraft that are custom spec'd and made by Eaton, that's a 130 lb/in spring. I run the discontinued AFCO 121 lb/in springs on my Duster, and they actually work pretty well with a rear sway bar and the 1.12" torsion bars I run up front. The Mopar Performance Oval Track springs that are being sold again are also 120 lb/in, but they're being made in Mexico so the quality may not be what it was when AFCO was making them. I have a set of the oval track springs but I haven't run them yet.