Can anyone tell me if this a good idea for a book?

I think the plot sounds interesting, but I don't think you should call the gods by the names of the Greek Gods. Maybe you can create your own names for each god, but the gods can still have traits of the Greek Gods. I only say this because it might get confusing if you call Aphrodite Ares's progeny when in the myths they were lovers. If you make them have different names, then it won't matter because then it will be your own set of gods and readers won't have preconceived notions on how the gods are related and whatnot.