I found these (
http://cgi.ebay.com/ebaymotors/DYNAMIC-SUSPENSION-SHOCK-COIL-OVER-UNITS_W0QQitemZ150405787715QQcmdZViewItemQQptZRace_Car_Parts?hash=item2304e23043)on eBay while trolling around. These are the ones that are from the old Shelby Series One cars.
A few builders scooped up some of the initial ones that were for sale about 1.5 years ago (for $400), this guy is now reselling his it would appear (for $650

).
I know that Pook and I got a set, someone else even had them dyno'd and posted the results.
They come with 200lb springs all around and are double adjustable.
Just thought someone might be interested.