600cc super sports - newbie to sports bike but not biking in general?

Going on your 8 years of riding you might be suited to a 600 sports bike with an improved rider coarse under your belt for the reason you haven't ridden a bike that accelerates, stops and corners as these two do; they are well worth the time and money even if you only pick up a few tips.

As to which bike, they do the same thing but feel a bit different sitting on them so I would at least sit on them both to see which feels best to you, ask for a short test ride if they have a demo bike or a used one. Either bike is an excellent choice...

You shouldn't have any problems with the 600. just a case of adjusting to the power levels.
unless all those other bikes were off road bikes. in which case I would suggest a quick trainer course.
some things are just a bit different.
You should try both the bikes out before buying. they may look similar, but they feel totally different.
I'm a lot more comfortable on the Honda, I find the Yamaha a bit small, and strangely enough the R1 feels even smaller.

I do suspect this is not a Racing question ?