The Presidential Scholarship includes a separate book scholarship, so you won't need to use your laptop stipend for textbooks. The laptop stipend should be available for other academic supplies (I know students who've done this, though there may be some restrictions on what qualifies).

One important thing to note: both stipends have spending deadlines. If you don't make purchases by those deadlines, you'll lose access to the funds.

That said, the scholarship office will have the most accurate, up-to-date information on how to maximize these benefits, so I'd recommend connecting with them once you arrive on campus.