You can keep playing with gearing until you find the sweet spot. Use math to determine the ratio you're working with, and then move the ratio up or down, according to your needs. You can also look at JT's chart here:
http://www.jtsprockets.com/fileadmin...tgearratio.pdf
Once you have the acceleration and top speed you can work with (it's always a balance), the next step would be "stage one mods" to help the bike breathe better and flow a little more fuel to compensate.