Yeah, don't bother with the REA book. Even if you manage to find the ETS book, IIRC it only has the first three practice exams in it. You can download PDFs of all four practice exams and print them off yourself for free.
As for physics reference material, you're on your own. It's not in the ETS book anyway. Gather your undergrad textbooks, particularly anything having to do with E&M, Lagrangian mechanics, special relativity, basic quantum mechanics (including solution of infinite square well and hydrogen atom), early pre-QM (such as the Bohr model, de Broglie, photoelectric effect, etc.), and thermo/statistical mechanics.
Use one practice test as a diagnostic to see what you don't know. Then study those things. Iterate. Make sure you time yourself for at least one test, to replicate testing conditions.