There are plenty of people out there that has run coil overs on the stock arms on the street. The stock lowers only need to be welded together to brace them and a small support bolt put through the back side of the LCA bushing to keep the bushing from trying to pull off the pin. I would however strongly recommend putting in some sort of bracing for the upper shock mounts as they were not designed to support the weight of the vehicle.
Here's a link to some pics of a nice setup:
http://hemiduster.com/coilover.htm