Might want to check with Addco on sway bars.... they have a good selection of them.... Maybe about a 1.125 on the front and a .875 on the rear??? Big heavy car is going to need a big heavy bar. I would also recomend the polyurethene bushings for them.

Another thought would be the torsion bar type sway bars....ProZ has them on the back of his Camaro.... Look great and a large selection of bar diameters and end links..... Might check with him and see where he got his at.....