I don't think anyone makes metal sway bar bushings, but I could be wrong. Polyurethane/ Polygraphite bushings or other stiff material is the best way to go I believe. Sway bars do need to move/flex a little. I also think metal bushings for the sway bars would be very noisy. Drag links or center links connect the pitman & idler arms to the tie rods & have no bushings, but I've seen center links made out of very light & very strong material to save weight for drag cars. The only bushing there may be, is at the point where the idler arm attaches to the "K" frame of the car, depending on what you have. Not all cars have the bushings between the idler arm & "K" frame. As far as Panhard bars go, I don't think ANY old Mopars have them & I think they are used mainly in coil spring & independent rear suspensions. I also believe they help locate the rear axle on these cars. But the stiffer you make the moving suspension pieces, I.E., control arm bushings, sway bar bushings etc, the better your car will handle. Fender bracing, chassis stiffening (frame rail connectors etc.) will improve any flexing on the car & that equals better handling. Just remember to put the full weight of the car on the wheels before tightening any suspension components so they don't bind up. Hope this helps somewhat.
