Can anyone advise what kind of connector I would need to get to modify my older BitZero to make it compatible with the S5?
Molex Micro Fit. But you might want to make sure your version of Bit Zero is electrically compatible. As long as it’s a V2 you should be good.
https://www.digikey.com/en/products/detail/molex/0436450300/268975
You will also need the appropriate pins and crimper. Check the datasheet.