try:
neurostim, deprenyl, pyritnol, piracetam, aniracetam, Acetyl L carnitine, Centrophenoxine (necessary if you are taking piracetam and aniracetam), vinpocetine, hydergine and ginkgo biloba.
Thats a pretty good stack to start with. You might want to add in omega 3 fatty acids and a multivitamin.
I take that stuff and I get in the top 5 grades in my courses at washington university.
Adderall is definitely good too...but I'd be worried about raising blood pressure and heart rate, as well as possibly screwing with your head (small chance of causing schizophrenia).
Obviously if you consider this stuff please look into it first.
www.avantlabs.com is a good place to start.