If you are completely new to helis, I would actually suggest a 50 size (600 to 620mm blades){600 electric}. This size will not be as intimidating as the 90 (700) will be and it will definitely grow with you as you get better. I'm not knocking down the 90, if your wallet can take it, go ahead Just do not be surprised when you crash it the first time and your wallet commits suicide with a broken credit card.
Rafael