It depends if you want to be stuck on a sportbike or a cruiser, since cash flow to get a F4i seems like it's going to take some time. Months of riding the 450 Rebel would be sufficient experience for someday getting the sportbike you really want. Though the rebel is a cruiser it will still function the same and allow you to learn accelerating, braking, shifting, countersteering, and how to get out of emergency situations you will encounter on the street.
"Don't be jealous that I've been chatting online with babes all day. Besides, we both know that I'm training to be a cage fighter."
"When I drink, something happens. This guy called Buzzy comes out. And he proceeds to do whatever he wants, I guess'' - Wayne Rainey