Once I got my permit I went out and bought a beater '85 Honda Shadow that was 500cc. I rode that thing for a week or two every spare chance I got before taking the MSF class.
http://nm.msf-usa.org/msf/ridercourses.aspx?state=MN
Once I took the class and got my license I went out and got a new R6. I think it was good for me to get a 600 as a first rocket as I don't have as much self control as others when it comes to having that throttle in my hand. I rode every chance I get and tried to push myself while still being in 100% control and feel like I've learned a lot over the past few years.
I wouldn't worry so much about getting a cool looking bike right away, just something thats a good deal. Chances are a lot higher that you will lay down your first bike or drop it. Shit happens. If you do drop/lay it down that super clean bike you paid good money for is now is damaged and you wont get your money back. I'd start off on a 600 or maybe even a cheap cruiser to see if you like riding. Take the MSF class to get your license and have fun. Rockets can kick your ass if you don't treat them right so I'd say ride within your limits and have fun