I'd go for the highest reasonable one. That way it'll either run great or be too rich and you can go down a size or 2 from there depending on how it runs. If it runs pretty good but start cutting out when you really goose it and get the rpm's way up, go down a size and you should be good. if it cuts out a lot even when riding less than WOT then back off a 2 or 3 sizes. thats how i've done my jetting and it's worked well, plus it's best to be on the rich side than lean.
