Looks like you are looking at and will be comfortable with a 600 and you want something in a race style bike rather than a more upright sitting sport-bike.
Are you planning to buy new? Are you planning to get something that will cost a total of $6,500 or are you using the $6,500 as a down-payment, because that would be a great down-payment towards the Gixxer 600 which would be around $9,000 new, not including taxes and other fees. I have a Ninja ZXR6. I also tried a Gixxer and really didn't find that much difference in handlebar position between the two. But then the Gixxer was an '03 and my ZX6R is an '07.
If you like low bars where you have to lean more forward, you may like the new models of Honda CBRs, which are pretty much Suzuki Gixxers mechanically and in looks.
I personally liked the cleaner look and solid color of the Kawasaki Ninjas myself and the way my legs fit against the sides and one of the reasons I chose it over the others.
If you are interested in starting on a 250, you may like the Ninja 250. It lists at $4K, so you could pay it off cash with your $6,500
You can probably find a decent used Gixxer or something at a dealer for around $6,500.