Bought a Techno CNC Patriot 1410... Now what?

Our local school was auctioning off some equipment and I secured a Techno CNC Patriot 1410 for $100. Score! The problem is nobody knows where the control card (PCI Servo Interface?) is. The best guess is "it got thrown away with some old computers."

Off to the internet I go! I've been in and around 3D printing for several years so I'm comfortable with a little DIY like this. So far I think I've narrowed down what I need to do to get functional to:

1. PC Interface Software: I'm leaning towards LinuxCNC for broad compatibility and I have several Pi4 devices collecting dust.
2. A hardware interface to replace the missing PCI card

As you can tell I'm early on this journey. I know that LinuxCNC can drive the machine (possibly after getting a new control card/motion controller) but I think I need the CNC equivalent of a Slicer in 3D printing, right? Something to render my models into corresponding GCode?

As far as the missing PCI card, a new one is $1,000 from TechnoCNC. That seems crazy. I've seen some discussion of the Mach 4 which looks like what I need (software and hardware.) Or should I be looking at the Centroid Acorn stuff? Ultimately if I can't get anything else going I'll gut it and use the enclosure for a heat controlled 3D printer. That just seems such a waste...

TL;DR; I bought a used CNC router missing a critical piece. Advice appreciated!

Congrats on the great deal!

We sell the pci card for 650 and fully support your machine 7 days a week. The team at Armor CNC were electrical and mechanical engineers at Techno before the name was sold in 2013.

Let me know if you're interested in keeping the machine stock. We can make a deal on a pci card + computer combo to save you some $.

We also have a kit to convert the machine to mach4 but it's more expensive because we keep it servo, we don't switch it to steppers.

Regards
Eric