the second stepper is technically the better option.
But the one linked with a belt is a decent option and potentially the easiest to calibrate.

If you have a bed p;robe and have two seperate z-stepper drivers on the motherboard (I have no clue on the boards creality use) then autowiz's guide to automatically levelling the x-axis is well worth reading.

I think the boards use one controller but have two z-motor sockets.
So you have to level the x-axis bar by hand - probably.

There should be plenty videos on how to do that.

I'm pretty sure it wouldn't be too hard to make a an adaptor that used the existing extruder and just pop it oon top of the hotend.

It's what i did with my sapphore pro.

If you want to spend some money then the biqu H2 lightweight extruder-hotend is a good choice: https://www.amazon.com/BIQU-Extruder...788141&sr=8-11

Me i like to modify rather than upgrade, so i'd make the existing extruder work :-)