My first bike was the Yamaha YZF750.

I think it really depends on the maturity and confidence of the rider. If, after taking the course and test you don't feel confident then you should definitely start with a smaller bike.

However, I recommend buying the bike you want to get as long as you are mature...remember with great power comes great responsibility. As long as you take it easy a big bike is the same as a small one in my opinion -- difference is that you won't out grow a big one.

that's my two cents...