I would like to say that you should take HL Economics. I do HL Economics and Physics and as of right now, HL Physics is very hard for me(There is a lot of math). From what I've heard, HL math is pretty hard, but if you are willing to do Economics in UNI, I would advice you to take HL math (Econ in UNI has a lot of math). HL Econ has more theory related (There is a bit of math), but it's more depending on your writing skills(BS skills).
Good luck in IB, wish you all the best. (頑張ろう！）
(Basically, don't choose IB physics, cuz you WILL die, unless your math concepts are very good, then go for it, but you're already planning doing Econ, Business related subjects, so don't do it)