I use a touch probe from vers.by on my Shapeoko, It has a 6mm shaft. I have their WL model (Wireless with replaceable battery), but looks like they only offer their rechargeable (WLR) and wired (PR) version now. I would just make sure you have enough Z travel for clearance.
Specs: Touch probes and tool setters Vers - vers.ge
PS, those Edge Finders should be operated at relatively low RPM (~1000), the Nomad is only spec’d as low as 2K RPM.