Either the official CRTouch kit or an imitation of the old Creality BLTouch kit. Creality doesn't sell the BLTouch kits anymore, but this kit will get you a genuine BLTouch and knockoffs of the brackets Creality used to sell.

Having used both, it seems to me that which one you get doesn't seem to matter much. They use the same cables and firmware, and the mounting brackets also work the same way, so setup is about equally easy (or hellish, depending on who you ask). The BLTouch is a little lighter, but not enough to matter in practice unless you're doing speed-Benchies. The CRTouch is supposed to be less susceptible to electrical interference, but in practice it seems to suffer about the same. Despite using similar cables and firmware, the CRTouch is not a clone of the BLTouch; the internals actually work quite differently (the 3DTouch is a BLTouch clone, though, so steer clear of that).

Really, either of these will get the job done.