Many state aquariums have coldwater systems on display. They're beautiful, and I think it's sad that there is not much available to us in that end of saltwater fishkeeping. It seems to be a specialty area, and I guess it's not profitable to set up special systems for a select few customers. There are some species that cross over into the coldwater realm from tropical but there would be arguments left and right as to "you can't have that", and "this would never survive" can you just picture the threads/wars on this site?