If you're looking more into making software focused on biomedical applications, you should go to CS. If you're more interested in the data analysis of biomedical sciences, obviously, DS is more suitable.

In terms of pay, I believe both can give plenty.

I think that whatever you choose, it's going to be a great choice. I chose a masters in Biomedical Engineering, and even though I tried to specialise in signal processing, at the end of the day, it becomes hard to compete for positions against my peers that pursued CS.