Check out the Yamaha Diversion 600 (Seca II). Fast, flexible and economical to run. Otherwise go for the Honda 500. UK bike couriers use them and they wont run anything thats unreliable or needs humungous maintenance. Couriers also use the Diversion 600. 60bhp, 55 per UK gallon and dont eat rear tyres. Plenty of go under 6000rpm, but wind it around to the 9500 limit and WOW.