how much do you weigh first off? reason i ask is if you are around the 250 mark then maybe a 750-1k would be good for you simply b/c of weight....if you weigh 130lbs soaking wet, and are new to bikes a r1 shouldnt be the first thing you look at

when i first started riding street bikes i bought a gsxr 600, i weighed about 200lbs, and had years of experience riding dirt bikes so the main stuff came easy for me

best advice i can give is dont ride outside of your experience, try not to ride with groups of people for a while (and if you do they should let you ride in the front, so that youre not trying to ride outside your experience level to play catch up to them), and always expect the unexpected, cagers pay no attention to anyone on a bike, always assume they are going to pull out in front of you, merge into your lane, or try to run you over b/c they simply dont see you. and remember the bike takes a lot longer to slow down than to speed up, so speeding in confined traffic is a no no and your begging to face plant into something

a lot of people say get a smaller bike, a 600 is plenty of bike for a beginner, but theres no reason why a beginner couldnt start out on a 1k if the person is responsible....only problem is when you get on that bike your head swells and your balls get bigger and thats where dumb decisions come into play

be safe, dont be cheap when it comes to buying safety equipment, and maintain a level head and you should be alright