If I subscribe to the online SAT Math Guide (the 3 month or 1 month) do I still need to get the physical copy of the PWN Math Guide book? Or is the online version the same material as the book?

The online version is a tiny bit different from the print version, but only because it’s more up to date. As I continue to work on revisions to the 4th edition of the physical book (to eventually release a 5th edition), I make those changes to the online version.