If you're thinking about painting (I am a steelworker with much painting/coatings experience) and want something that will look good, I have a few suggestions.
You look like you have a pretty extensive brewery so if you're willing to spend a little money, a two part epoxy paint will cure like steel and thus be really easy to clean up and will withstand a tremendous beating. Since you're in the states, I would suggest Sherwin Williams Duraplate-235. It will run you around $100 for both parts of the paint.
Another good coating would be a High-Solids polyurethane (again a two part mixture) It cures like a rubbery plastic but is easy to clean and would probably serve the purpose well.
But if you're like me and don't want to spend $100, an Industrial Alkyd Enamel would do the trick (I think its like $20-$30 for a gallon) just make sure go give it a long time to cure.
Also I would recommend a roller versus a brush for the above three, it will come out thicker on the particle board and will last longer, plus it will look better.