ProDesk3D - No software or Drivers, Help!

[curious aardvark]

well I'd be inclined to try repetier or marlin first and just see if the board would talk to the machine at all.

At the end of the day, once you disconnect the existing board you've got the standard cabling all printers have, so can't see any real reason you can't simply start with normal firmware and just a couple of the extruders plugged in.

[Trakyan]

You won't need to code much for the arduino/ramps, at most changing the config files (lots of guides online on how to do that, not hard and you'd need to do with with any controller board you end up using). Just download marlin, repetier or some other firmware from github or elsewhere. But yes, for the arduino, ramps and driver kit you'd need all three as seperate components. There are plenty of places online to get them as a bundle and they cost about $10 total. They just plug into each other, just be careful you don't plug in the stepper driver boards upside down (easy to do) as they will fry, not an expensive mistake but it sucks waiting for replacements.

RAMPS is definitely your cheapest option just to get it running, and it can run multiple extruders (2-4 I think based off if you use the expansion board, but don't quote me) just not 6 of them.