USB is not very good for a plasma, I strongly recommend you go with Ethernet.  Please check this FAQ Post:

https://www.cnc4pc.com/faq/article/why-use-ethernet-connection-for-my-motion-controller

Keep also in mind that most of the import USB motion controllers do not handle discrete I/Os in real-time, so they end up being handled by Mach3.  That is why THC does not work well on those.  Maybe the C94 or C25XP are good options for your project.

I am building new plasma table looking to go with MACH3 but I would like to have a THC-1 found on this site on table and was woundring if anyone has use this combination.