I think the real problem is the "added" downtravel.

The shock mount as you described needs to be moved now. I don't think you will find a true proper fitting shock. All your added supsesnsion travel is going down and is no longer balanced like the factory settings. I would suggest to just get rid of the bushing underneath the shock mount for now. That should help.

As far as the Rancho shock, I believe that one was for the Rancho lift kit for the Pathy/HB and is no longer being sold since Tenneco bought them out. Kinda a cool shock, the adjustment knob sits up top. A serious POS lift though.