I applied to both social psych and organizational behavior/management types of programs. I didn't apply to both in the same school, though I have heard of people doing that as well. I think they are really related so I don't think people look down on you applying to both types of programs (and if it applies, you could want to look into I/O psychology programs, although that might be more related to my situation than yours?). Here's what I can think of that compares the two types:
* The research is very similar at both, but there is a difference between who you teach: undergrads/graduate students v. MBA types of students (and maybe also sometimes undergrad business students?).
* Funding is a lot better generally at the business schools, and when you come out of the program, you're likely to become a business school prof (and therefore make more money), and it's true that sometimes psych phds go and work at business schools, but I don't think I have ever heard of business phds working in psych departments (though maybe there's no reason to for them because the money is better where they are).
* Classes - you will obviously be taking more business classes at a business program, though it is likely you'll be taking a lot of psych as well (but how much depends on the program I think). You could take business classes in a psych program if the school has one, but that would be more on your own accord.
Hope that helps (sorry if I repeated a bunch of what's already been said!)