Hobarts are pretty much the only dishwashers I'm vaguely familar with.
Since the community centre will have traffic, a commercial dishwasher will help if
you don't have the time or manpower.
But unless I'm tired, I rather wash by hand than sticking things in a household dishwasher as it simply takes too long even on Fast mode.
It all really depends on factors with the volume and flow of customers, whether you have enough crockery/cutlery so that you may or may not have to wash used ones immediately, etc...
If you've got a steady supply of volunteers, why waste money of expensive and harsh chemicals.
In Aussie dollars, brand new commercial undercounter dishwashers start from around $3000 and pass-thru dishwashers from $5000. And that's simply the dishwasher, excluding the costs of installation, chemicals, etc...
But what I'll definate get is a pre-rinse spray unit first, seriously it's amazing what high pressure aerated water can do.