Welcome to the forums!
For your HMI, I would be giving [I]groov [/I]a solid look over.
Put an ipad in an enclosure and go with that. (Dont forget they are made out of Gorilla Glass, so once in a solid case, they are pretty strong).
When all is said and done, it should be a little cheaper than a PC and touch screen up front, but factor in running and maintenance costs, and you should be way out in front.
If you can get by with a 7 inch screen, then something like the Nexus 7 for 200 bucks should really shine.
Put the touch screen at each oven, and then a single PC in the office running PAC Display for your recipes and long term data logging (and email alarms if required).
[I]groov [/I]and PAC Display work seamlessly with our controllers, it really is a plug and play all round solution.
You can email or call our pre-sales team and they can give you a demo.