I would definitley reccomend a 600 as a starter bike and I personally don't even look at anything over the 600 - 650cc range, and I have been riding for some time now.

I wouldn't however reccomend the R6 as a first bike but do as you wish.

The bikes you listed are all good bikes but I would stay away from the Buell and the Triumph just for reliability factor. I also suggest you look at used bikes over new, because you are going to drop it (everyone does) and its easier to walk off a used bike being dropped than a new one