1) Dont take both - econ over business
2) You don't need econ for econ at uni, maths and further maths would be better, so if you apply and say econ isn't offered in your school, it'll be okay
3) you don't need econ gcse for a level, if no one offers it, can't really do anything
So just choose maths, further maths, geography/history/language and something you enjoy