Well I'm a bit biased.....
As are many of my friends....
The Hayabusa is in the class considered Sport Tourers. The bars the grips mount on are called clip ons and they are above the triple tree which is the bracket the forks go thru. On most real sport bikes they are below the triple tree and really do cause one to lean over. The Bus is a very comfortable bike. I rode mine to North Carolina and back no problems. My friend you see with the dog has logged over 100k on his just like that.
If it were me I'd buy a bike I could grow into and never outgrow. Ferraris don't immediately go fast or get people in trouble. And neither do big bikes. Your life is in your right wrist. If your cool and level headed you'll be fine. We have a member on the Busa forum who's 22 now but three years ago bought his first bike which was a Busa. We all thought he was gonna die in a week. But 30,000 miles later the rubber side is still down with zero incidents. Really has proven many members there wrong on the baby step method of bikes.
Bikes your should look at that I'd suggest would be of course first:
The Zx14 or the Kawi Concours which many of my friends are switching to.
All three would be bikes you could never outgrow. While I cruised around and enjoyed Sunday rides I also had more Hp between my legs than most cars and even in 5th gear that thing would pull your arms off if you dared. So from zero to light speed the only thing you'll be happy with is a liter class bike or above. If you go the 600/636 route you'll be tired of it again in a year or so.
Think about going down I95 at 80 and a tractor trailer passes you. My bike would not even budge from the wind force. I'm sure on your bikes you've felt the push from these big rigs going by you or trying to pass one. A 1000cc and above sport tourer will remain rock steady on the hgwy.
And if you should get the itch and find two to three miles to grip it and rip it trust me the adrenalin fix will last for days...