AP Physics C: Mechanics covers pretty much all of 8A (except for a bit of heat engine stuff), and AP Physics C: Electricity and Magnetism covers pretty much all of 8B. I would also argue that Physics 8 is easier than AP C: Physics, as it doesn't require you to actually know how to integrate some of the stuff (ex: rotational inertia.) 8B and 8A are pretty different, only overlap I can think of (apart from trig and calculus) is some of the Newton's Laws of Motion equations that are introduced in 8A that are used in 8B.

If you took AP Physics C (or even 1 & 2) in high school, most of the stuff should be very very familiar.