If you say you love business, then take it.
Economics is more respected i guess, but if you're looking to do business management in uni, then business studies seems like the better choice. Also, aslong as at A2 your traditional subjects outweigh the non-traditional i.e. business, there should be no problem about it being a "blacklisted" subject.
Besides, you'll probably have more to write about on your personal statement as to why you want to do business management in uni from taking business studies since its more directly related to the course, rather than having to tie in eco to your choice of course.