Drive options for steppers with encoders?

Have a very small mill that was fitted with steppers with 500 line encoders. Need to get motor drives. What are the options for controls that won't break the bank that are compatible with linuxcnc?

Steppers don't usually have encoders, are you sure that is what they are?

What are the motor specs?
What size are the motors? How much current are they rated for?

The motors are clearly labeled (with the OEM label) "1.8 degree step motor" from Compumotor, OS series. Current rating is 3.7A. Encoders are 512 line HP/Agilent/Avago (they have changed names several times) encoders. I wasn't able to find the exact specs of this motor on the Compumotor site - it may have been custom or custom labeled. The encoder mounting looks to be a factory job. I could just run them open look but was wondering what it would take to use the encoders. The motors were retrofitted to the mill I have - the work was well done but clearly a retrofit. I need to put together the motor control and am wondering if the motors are big enough for the machine. You can see the machine here:

Guess I can't post links yet....

It's on cnczone site at forums/benchtop-machines/282060-servo-products-cnc-mill.html

compumotor had step drives that used encoders. They were still step/direction dives and can easily be used with linuxcnc.
I have one i believe its a S6 or SX6 drive (i dont use encoders) they use special motors (110 volt)
compumotor also had serial interface IFAIK but I doubt the machine came with that.

Chris M

s6 is the step drive, sx6 is an indexer (you don't want that)

the cheapest i could find was PICO-systems USC and i am using longs motors steppers and drives from Ebay
Here is a link so you can see my machine for reference
www.youtube.com/channel/UCiRqg_iQ-jsIcW1eX6On6hw