I don't own the Biggest Loser books or DVDs, but I'm fairly certain they're a bit different from Jillian's book and DVDs, which I do own. (Maybe someone who owns both can be a bit more help)
What I would do is order the Biggest Loser book, if only to compare and contrast with Jillian's. It wouldn't hurt to see how both function/work. Maybe see which one is best for you. This forum has threads on both JM's and BL's workouts and eating routines (hesitant to say diet).
You may could poke around in those and see what everyone says.
I'm not a lot of help, I know. But I can't stand a thread to get a ton of views with no posts.
Good luck.
--B