I haven't taken the boards yet, but based on what people told me and the nbme practice tests, I'd say that really FA is the way to go.
(well, one of my classmates, who just took it, said all the drugs on her exam weren't in FA...but I think she was an exception to the rule).
One thing tho: I find it useful to read parts of Katzung & Trevor's Pharm, Examination and Board Review. Yes, it is a big book, but it is really useful as a reference with FA (FA pharm is based on it, so it is easy to follow). This is because Katzung is very clear on the mechanisms. Roadmap Pharm is a miniature version of this (I think it's written by the same authors), so you might find it useful, if you really have just like a day left.
Good luck!