Big Guy - Riser Kit

I have an 03 Sv650s.

I am a big guy - 6'5" 220lb and was wondering if adding a rear riser kit would be worth while. I find its suspension a little heavy on the front and soft at the back. I have the suspension setup stock except the forks which I had rebuilt after a crash last year.

Would it be a worth while investment to upgrade the rear shock as well as risers? If so what do you guys suggest, you guy will know more about this bike then I will since I haven't been riding for too long.