[speediva]

*chants* Busa! Busa! *end chant*

Okay, joking. Um, my personal vote goes for R6 or a Gixxer 750. I don't have any idea how old you are, but atleast you've been riding for a few years. The R6 has a ton of power and is nice and light on the track (since you mentioned track riding). It also would depend on if you want to stay stock or go for aftermarket... I honestly don't know what would have the bigger aftmkt. pull, so that decision would be up to you.