Hey Pete,
Sorry, I know nothing about your shocks. If you can't find the answer here, I would post the query on
The Boxerworks Forum. I guess registration can be tough there (ask Sue in Canada), but there is a lot of knowledge there.
As far as redoing the seat foam, the only special tools you will need is a electric carving knife, for shaping the foam, and maybe a pop-riveter for reassembly. Some spray glue as found in hobby stores is needed.
I took the easy way out and had mine done by a local car upholsterer that was recommended by three different sources for doing bike seats.
Then again, Sue used this same foam for her LS, and she and a friend did the work themselves.