I followed the build on Project Responder a long time ago, and have to say it was an excellent build article, and badass truck to boot. You guys didn't leave much of anything undone on that truck.
Anyhow, are you sure that you want to go to coil springs in the front? Leaf springs are a hell of a lot simpler and more reliable setup, and they aren't a super pain in the *** to adjust. For these reasons I'm going with a reverse shackle leaf setup like the one you are currently running to convert my F-250 to 4x4, when I was originally going to do a 70's style coil sprung suspension.
If you are dead set on it, the ultimate suspension would be a 4 link setup in the front with coilovers, which can get pretty pricey. You could also look at a stock suspension setup from either a '79 and older pickup with coil springs, or look at an '05 and up Superduty setup. This member is running the '05 radius arms (these are beefy as hell) on his pickup with a homemade setup:
http://www.460ford.com/forum/showthread.php?t=147249