I never took the SAT, but I doubt the vocab would be the same as GRE. The two tests are targeted at people with very different levels of education. From what I understand, the GRE verbal is trickier and more convoluted.
Anyway, I took the GRE the other day and got a 166(96th percentile) on the verbal portion. Two months ago, I purchased a Kaplan GRE study book and answered all the practice questions on it. Then I went through the 10 practice sets on the internet that came with the book. I did about 5 of the quantitative practice sets, and 2 or 3 of the full-length practice exams. I did this while also taking classes, so I'd say you should be fine, assuming you generally do pretty well on tests like I do.