Upgrading from vista to windows 7 on an ssd?

[alpha fox]

Hey everybody, I am putting an ssd in to my build (60gb mushkin) as a boot drive. However, I am wondering what if there is any downside to installing windows vista on it and then upgrading to windows 7. The reasons I am doing this is I'm a student and our tech shop has oem vista business and windows 7 ultimate upgrade for $50, however no oem windows 7. So I am wondering if there are any drawbacks to installing vista and then 7, an if i should just spend the extra cash for an oem version?

 

[alpha fox]

Not sure, I have never used an upgrade version.