Mesa cards or parallel port? And where to learn about Mesa

Thanks, I had looked at those dealers but with their mark up it's something like 20% more expensive after shipping.

I've ended up shipping from the US this seems to be the cheapest option.

Thanks again for the help, I'm sure you'll be hearing from me again.

You wrote that you were considering a tool changer. Calculate how many inputs and outputs you will need. If you miss them, consider a combination:
7i96s + 7i84

If you want to make a control panel with many buttons, I recommend a combination:
7i96s + cable DB25M-IDC26 + 7i74 + up to 9x 7i84

Of course, you can start only with the 7i96s itself and buy other cards afterwards.

There is also the question of whether the closed loop motors you are using have an encoder output and whether you want to introduce it into the LCNC.