I would send the cylinder off to Mat Shearer or Arlen at LED that can port the cylinder to their pipe, K&T will do a good job also just be open to other builders.
The bad thing about a OOF pipe is it changes the look of the bike and people will expect it to be faster just because of the looks, so you better back it up or you will be teased even more when the banshees/450r beat you.
We have had real good luck with the FTZ inframe drag pipe, I am not saying its the best out there because we have not tested but the esr5 and 11 pipe against it but out of the 3 inframes the FTZ has worked the best. We did try a used FTZ out of frame that we hated but I think it was for a stock bore or was a early design and the header section of the pipe was much smaller than their inframe pipe and that is one of the most important sections of the pipe
Methanol would be a great power increaser, it does come with a down side, first your mileage will be cut in half compared to gas and you must purge the alcohol out of the carb and engine by running your normal gas premix at the end of everyday, but it will add almost 10% more power