Thanks to everyone who replied about the MA/MFA debate- they are both terminal degrees, but the reason I think I would need and MFA as well is because I want to teach at the university level. I spoke to a professor at SFAI and she said that I would in fact need an MFA, and that the british system isn't really compatible with the US one. People in the UK can teach at the university level without an advanced degree, so I think that is probably why.
I'd really like to know If anyone has a good sense of the program at Pratt though, as I think it would be good, but I've heard mixed things?