Keihin style Factory Pro main jets up to 250 here (series 393)
They have the slow jets too (series 21):
http://www.factorypro.com/products/J...hin, buy.htm
DynoJet jets and Keihin jets have different numbering systems so keep that in mind. Keihin numbers by flow rate (200 main = 200 cc/min) and dynojet numbers by hole size (200 = 2.0 mm)
Rough conversion:
Dynojet Jet to Mikuni Jet simply multiply the Dynojet size by .9375 i.e.: DJ200 X .9375 = 187.5 Mikuni Size.
Mikuni Jet to Dynojet Jet simply divide the Mikuni size by .9375 i.e.: 150 / .9375 = 160 or DJ160 Dynojet.
I don't think you'll need larger than a 58 slow. You should't have to rejet because of the heat...maybe adjust the A/F screw. I don't like to jet when it's very hot or very cold...sort of middle temps 65 - 75 and bike seems to run well enough at all temps. Guess it depends how picky you are.