[userbinator]

In regards to cheap whiteboxes, no such options allow access to GPIO ports.

The parallel port on older PCs works reasonably well as GPIO; you can get expansion cards for those which don't have one (they seem to have gone up in price now but they used to be extremely cheap.) Since this is an actual external interface it will be more robust than the GPIOs directly connected to the SoC of the RPi, and if you use expansion cards you can just swap them out if they do get damaged.