For the same reason I was going to do the Kwak rear shock mod, i had researched this quite alot and recomend you do the same. You need a shock from a 06/07 ZX10R. I even got as far as buying the shock, but have opted to buy a new bike when I'm back from my France Tour in a couple of weeks.
Mod details.
http://forum.svrider.com/showthread.php?t=80387
Shock for sale.
http://forums.sv650.org/showthread.php?t=168657
Regards,
Peachey.