Hiya, there are plenty of SV-specific longer dog bones to drop the back down (Longer dogbones lower the rear, shorter ones raise it) Lowered seats are a good way to go. The front yokes on an SV can be dropped between 10 - 15mm down the forks to level it out a little, we found 20mm on the K5 SV650S was too far and the forks were touching the bottom yoke when fully compressed. I would say 15mm *should* be ok, there's certainly a little room left with them at 10mm.
Please make sure you set the preload properly, there is a tendency when lowering a bike to "back the suspension off" by taking all the preload adjusters to their lowest setting. It makes the bike handle very poorly and doesn't give nearly as much ground clearance as you'd think.
*edit* I can't see from your post exactly which SV 650 you have, putting up year and S or naked will have an impact on available parts.