Thank you all for your input. Most of the suggested boards require too much work on the software and I/O interfaceing for such a low volume project. I have stored the options for when the volume of this, or another, project exceeds the expectations.
We have decided to go with the fdm88, which I stumbled upon during this search. The most obvious downside right now is the ladder programming. But this is such a small control program that I think I can manage. And if not, we have people in the company who are much more familiar with ladder programming who can help or just do the 'entire' software.