The issue with Enfield is that there no bikes larger than 500 CC. If you have ridden a 250 CC beforehand, it is better for you to look for atleast a 700 cc.
For that budget, my money would be on a used (say 2009 or so) Ducati Hypermotard. Handles well, upright riding position, desmodronic engine, boat loads of torque, an absolute riot to ride, and yet it is still quite functional. Only thing you have to keep in mind is that the upkeep/parts cost is going to be significantly higher than Japanese brands. I don't know what your riding skill level is, but since you mentioned a Hayabusa, if you are looking for an all out street machine, the BMW S1000RR is unbeatable for the money. Keep in mind, that you should select a bike within your skill level. a liter bike may seem cool on paper, but for a person with limited skills, they will be scraping them off the sidewalk within minutes.