I am new myself and just completed the course 3 1/2 eks ago and was initially thinking about the Honda CBR600 myself. I have many friends at work that suggested that I don't buy a 600 because in about a year or so you'll wish you had the 750 or bigger. Needless to say I didn't get the 600, neither did I get the sport bike as I fell in love with the cruisers and ended up buying a 07 Shadow Spirit 1100. All I can tell you is get what ever you want because you will even hear here that your first bike should be a small one in case you drop it. Need I say I've seen people drop small bikes too? Bro find one you like and feel good on. As a new rider you probably will drop it, I'm in the same scanario like you I just haven't dropped mine as yet and already have 689 miles on it in three weeks.
BTW I am a little guy weighing in at 115 on a good day. Good luck and be safe