I'd suggest a set of triangulated 4 bars, they eliminate the need for a Watt's linkage or panhard bar and with polyurethen ends they are very stable and work very well on the street... I'd build them with some DOM tubing, thick wall that will thread to 3/4" then use a 3/4" X 3/4" polybushed end. It's only necessary to have one end threaded for street use, I usually have the rear fixed and the front adjustable. Mount the coilovers on the back side of the rear end and keep them vertical as viewed from the side and no more then 30 degrees in at the top as viewed from the rear. I like mine in about 20 degrees at the top, makes for a good ride and still keeps the rear nice and stable.