Best bet is to make contact with your local refridgeration engineer, he will know whats about and may be prepared to go with you to look at any you find (I expect that you will have to pay for his advice but you never know, he may like venison!) It is difficult to find trailers and vans with rails in the roof as most chilled produce is palletised now. Think hard before you buy as often things that look like minor problems can be costly to put right. JC