ebay might be a good place to look too. i found an extra shock for $7.00 shipped. yes seven bucks.. (and it would be a local drive for you on where it was when i bought mine.)
also some people have converted to the R1 rear shock and i think the R6 as well, some modifications are needed, but not too hard if i recall correctly. Just to broaden your search a bit.
I love my FZ6, but the two things I am disapointed with are the seat, and the rear Kicking over bumps.
For the seat, I have a 1 hour ride to work, and the seat is OK. I would love a TS, but $350 is way too much for my needs. I am always moving arround, so I don't really get sore or anything, but I would like to try sculping a seat to fit my needs. I don't want to do it with my seat unless I have a back-up, so I'm looking for a cheap spare someone does not need to try sculpting.
Regarding the rear shock, The bike Kicks going over bumps, even when standing on the pegs. I am 230 and always ride alone. I am a shock engineer at an automotive supplier, and would like a shock to test. [Our company also makes shocks for the Aprilis, ducatis, BMW, others in Italy, and a few ATV shocks] Then possibly rebuild with different valving, and do some experimenting. Combining work with pleasure. I can live with the bike as is, and am not looking for better handeling or anything. Lately it's been slim pickings on e-bay. I would consider trying an R6 or FZ1 shock.
sounds like a fun little project! if you figure anything out then share it with the class, i also need to work on my rear shock, but I was just going to re-spring and add thicker oil to it, that made a HUGE difference in the front.