You already have an adjustable needle jet, so there's not much to gain in the dynojet kit.   I would just follow the jetting advice on this site and save the money for other fun stuff.
Basically, you have a drag pipe, now free up your breathing on the intake side.  Go a step or two richer if your jetting was o.k. when you were stock.  Elevation and weather  make a big difference too.  Go leaner as you go higher, hotter, and more humid.