The Busa shock is supposed to be a good choice. It raises the rear ride hight,but I'm not sure how much. I have a GSXR shock from a 1100 W That I would let go for $40.(plus shipping) It raises the rear ride hight 1 1/2". I have a Works Performance on my "98",it keeps the stock ride hight, but I had a pair of bones made to raise it 1 5/8". I like the extra hight for ground clearence when I get a chance to go to a track. Progressive makes a decent shock, Roamer had his for sale down in the parts section,but if I remeber right it might be sold already.
Once you get a good shock on the back,Race Tech gold valves and springs makes a huge inprovment on the front. That would run about $300. (not including labor) You set up the stacking order to your wieght and type of riding. Or you could just put a set of Progressive springs in and would be a improvment over stock. Dan