If you set your static sag, and then check your race sag, you might find that your spring is way too stiff for your size. At about 1 inch static sag, you should have about 4 inches of race sag (I posted the details of how to measure in an earlier post). My guess is that once you set your static sag, your not going to get anywhere close to the proper race sag, which means your spring is too stiff. If so, swap springs, and your ride height will improve.
However, if you are, uh, errr, big boned, and your race sag is right with the proper static sag, the pull arms are going to be the way to go. You will also need to drop the front forks in the tripple clamps in order to maintain any kind of steering angle (depending upon how much you lower the rear).
Good luck.
Rick