Good luck with your course, and have fun!! As far as beginner bikes, honestly, i think a r6 or even a f4i are great beginner bikes. Regardless of what everyone says, as long as you're responsible and have control over yourself, you'll be fine. A lot of people i know started off with newer 600s and are doing great. Also, since you are taking the msf course, you will have a better feel to what to look for while riding. So i say go for a newer 600 bike so that you will not regret buying an old bike only to regret it and sell it to buy a nicer bike.
my .02