You will probably want to go for the B.S. and it wouldn't hurt to minor in biology, geology, chemistry, anatomy or botany. You are going to want to go towards more "physical" oriented classes rather than "cultural".

You will be focusing more on archaeological and osteological recovery so classes that familiarize you with field techniques, collection of data, history, geology and other hands on stuff.

Many Anthro departments have programs set up so that if you know which field of anthropology you'd like to go into, they can make sure your degree is tailored to that need. The department's undergrad adviser can usually help out on that front.

I imagine you'll end up on the B.S. track if your field is physical anthropology, but a BA with a concentration in bioanthro might also happen.

I think it is important to note that if you want to be a forensic anthropologist you're going to need to go to grad school, and most grad programs I know of aren't looking for a strict set of pre-reqs. I mean, if you were to take vet schools for example, they often have pre reqs calculated down to the number of chemistry credits you took as an undergrad. Anthro is more laid back about things like that. Heck I know a bioanthro masters student right now whose undergrad degree was in engineering. so if the difference is between getting a BA in anthropology or a BS, you're still going to be in the clear.

Always go for the BS if you have any feelings about working in Anthro later on. It will help.