Sportbikes are commenly categorized largely, first, you should look at the bikes as two categories. Sticking with Yamaha, the R1, and R6 would fall into the superbike category, and the YZF600R into the Sportbike category. This is also sometimes referred to as a more sport-touring type bike. The 600R is basically the same setup as an R6, except it's one long seat, and minus the EFI. Also to insurance, it is not considered a race bike. This may be a good place to start with your folks, you would be then willing to compromise. Plus riding a cruiser going right to a race bike/superbike is quite a jump. Once you have a year or two on, what I suggest a 2-3 year old bike, then sell and get your R6. Buying a used bike first is good, not only if you put it down, but when you go to resell you will not lose that much money.

I bought my first bike for 3400, and sold it 6 years later for 2700, only upgrade I did was a used pipe from ebay. Not much loss, and yes, it had gone down.