You may as well start off with one of these then:

https://phillipscorp.com/india/phillipsgrinding/phillips-sur...

All you need is a serial port and some G-codes.

Surface grinders generally don’t use CNC, they are a simple machine.

In the 1950's, yes. But these days they definitely are CNC based.

https://www.rooy.nl/en/areas-of-expertise/surface-grinding/

This is a fun playlist of a conversion of a manual machine to CNC:

https://www.youtube.com/playlist?list=PLDlWKv7KIIr9rlCwZ9K43...