where in the U.S.A to buy parts four coil overs

[piledriver]

I ended up welding proper kevlar-lined Heim ends on the Bilstein SGs, as the supplied screw on units were junk.
I also shortened them an inch and repurposed some KYBs into external reservoirs, making for a really short shock with full stroke.
This worked best up front, I ended up with 2010 digressive valving up front with 100 lb/in 12" springs, using the Bilstein kits, but the Smileys racing kits work fine.
Front torsion bars installed at-rest. (type3 so splined similar setup to rear bars)

For the rears I found some $40 "surplus" FOX 2.0 "Truck"//Ridetechs for a 1500 Chevy van, had stems on one end, removed stems, rearranged the valving and welded heims onto the stems, coil over kit from A1 racing was a "heat shrink" fit on the Truck shocks, which are much thicker wall than std Fox 2.0s.

I used Ford HP fuel pressure test ports (1/4" flare like AC) for all the schrader valves, and used my AC service setup to evacuate, degas, and fill the shocks with Redline "like water" fluid.

Used 250 lb/in 14" x2.5 coils out back, with the torsion bars installed at rest.

Day Racing in Tyler Tx supplied the Bilstein shim kits, great folk, and next day US mail for me at least.

I have detailed data on valve stack etc used if anyone cares, the f/r frequency offset works great at highway speeds no porpoising.