I have a stock rear shock from my '07 919 that I just listed on eBay. The listing is for both the rear shock and front forks but I could revise it because there are no bidders yet. Or I can make you a good deal on the full suspension set.
I'm selling both because I upgraded, so there is nothing wrong with either. The bike had 15k miles when I took them off. Let me know ASAP if you are interested.