Daniel -
Funny, I was just thinking about this over the weekend.
There are some inexpensive (under$1k) glycol recirculating chillers used in the beer world to cool the lines that go from the kegs to the taps. If you built a chocolate cooling slab (like this one: http://www.dr.ca/chocolate-cooling-slab.html ) and filled that with glycol, and then pumped the glycol from the chiller through a pipe - like a radiant heated floor - then you would not have to freeze the slab, and the glycol chiller would take it down to 55 or whatever temp you set. Total cost could be under $2k depending on the size of the table. Size gets to be the real issue here, and that's dependent on batch size.
:: Clay
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