Gearing for supermoto on 98 FE501?

Mine came stock with 15/42 long ratio trans. a top speed just over 100mph, gets there quickly, and isnt horrible to cruise with at constantly around 60mph or bewteen 30-80mph in twisty-straights. i currently have an 18 inch wheel, 16 front sprocket, 43 rear sprocket and is definatly too slow to be fast but keeps revs down on my 20mile route to work. still can probably pull only a little over 100mph. i think it will be nice with 17 inch wheels but thats a ways out till i try it.
18/16/43 is still enough to get silly, earlier today my right hand was faster then my left and lifted the front off the ground in the low 40's on a third gear shift with me sitting forward on the seat and not trying.... a second later the front wheel touched the ground at just under 60. what can i say it was a stressful day at work :x

Do you have a way to measure the rpm's? i was just curious what rpm's you would be pulling at say 60mph with the 17"rims? You will rip in the corners i am sure it will be a blast!