Ahh Ok I misunderstood the question. Im no expert but from my experience the best setup for both drivabilty and handling in the rear is a custom rear leaf spring setup its not flat like some ive seen. It has reverse eyes both front and back so it still has a bit of travel but sits 3" lower It has shortened bump stops and modified floor pan to clear the diferentail. the shocks had to be changed as the stock length ones where bottoming out from memory.
It has an extra leaf and also a half leaf at the front to help stop tramp. We fitted the extra leave aftre teh lkast power upgrade as the ca tourque was starting to make a nice S shape out of the springs bending the front up.
The setup I have now I bought from and was moddified bye John Taylor at pedders in sydney he has raced 1200 for many years with lots of sucsess. not much helkp to you being In USA I can take a picture and scan it in if you like to comper teh stock spings to mine??
Cheers Andrew