Business HL and SL are extremely similar. I don't see why someone would take SL instead of HL. The main difference between the 2 of them is the IA. The SL IA is basically just a commentary on a business, largely based on secondary research; whereas the HL IA is more like a business report, and has to be done using primary research. That's pretty much it tbh.
However, when it comes to the content itself... HL students look at topics in more depth, with some extra added subtopics in each chapter. Also, the SL paper one is 1 hour 15 and the HL paper 2 hours 15. The SL paper 2 is 1 hour 15 vs HL with 2 hours 15. So just a slight difference in times because of the added content.
I'm in year 2 now. We finished the 5 topics in less than a year, and are now focusing on our IA's, CUEGIS and Revision. The SL students finished slightly earlier than us, but had a bunch of free periods in between.
I recommend that you evaluate your options, looking at your other possible HL and what you actually need for your desired uni course.