I bought the Progressive 412-4253C which is the 12.5" replacement for the stock set, a direct bolt on and (to me) a real improvement, hard bumps are still hard bumps but they really took the "jangle" out of uneven pavement.

I also installed the stock length Progressive fork springs and that is an even better improvement over stock (again IMO). I would recommend changing the front springs first and riding for a bit before I changed the rear, it makes that much difference and it's the most cost effective.

A positive attitude may not solve all your problems, but it will annoy enough people to make it worth the effort. Herm Albright (1876 - 1944)