I do Edexcel Business GCSE, and everyone says it's "an easy 9". Most people in my school get grade 8/9, but I go to a grammar school so it might be different for you. I was predicted a 9 in year 10 mocks. There are 2 papers in Edexcel business, and 2 themes, theme 1 for paper 1, etc. There are a LOT of overlaps between the two themes so some of the content is repeated.
I would do business for the high grade, but one thing about business is that i find it's very boring. I think you should do your research - look into the specification because that will help you understand the topics you will be taught and you can see for yourself if they are interesting.