To put things into perspective, on a scale of 1 to 10, 1 being the easiest bike to master and 10 requiring the most skill and experience to ride properly.
I would put a 50cc scooter at 1, a GS500 at 5, an SV650 at 6, a GSX-R600 at 8.5, a GSX-R750 at 9, the 1k at 9.5 and the Busa at 10.
While the difference between 600cc's and 1,000cc's may seem huge, after all we are talking about only 60% of the displacement the power difference isn't that great, you still have 75% of the dyno power of the 1K and probably about 90% of the real world power of the 1K because you really have to wind them up to notice the differences.
The step up from any non "R" motorcycle to any gixxer is a huge step up, unlike cars that marketing gurus put stripes and mags on basically a base car and call it sporty. R bikes are very very close to actual racing bikes, it's not so much the power either, it's the power delivery, it's hair trigger controls on the throttle and brakes that'll magnify the newbie mistakes you will make.
The first few months are the make or break ( in this case we're talking bones ) period a rider must go through just learning the basics and making mistakes, don't turn a learning experience into a life or death experience. The experienced riders here all know somebody who has been injured or died on a bike. Most experienced riders here have crashed their bikes, the most common thing we hear is that they were already down before they even realized they were going down.
Get a used, moderatly powered bike for your first season then you can think of trading up ( any money you lose on the bike will be made up by the money you saved on insurance ).
BTW have you even looked into insurance ? If we can't sway you away from a R bike maybe the humongous insurance premiums will.