Sorry, didn’t realize from your original post that you already had a Ninja. And that you were only interested in the sportbike style.
Then I saw the other thread where you plan to try the BRC again this weekend, and hope to pass this time.
IMO, if you already have what most folks call the ideal starter bike for the sportsbike fan, and you haven’t been able to pass the BRC yet, then you need to put in some serious miles on the bike you have before you start shopping for a liter+ bike of any style. And don’t assume an older 750 will be less power to handle than a newer one. Just not true.