Here is a link that Rainwolf sent me about using those shipping containers that liquids come in for the food industry. They can be picked up off craigslist pretty cheap at times. Especially for what they are.
Heres another one. I dont have space downstairs in teh baesment to get the IBC containers. I do have an ebb and flow system that I made with square 4 inch tubing though.
I would think that in a greenhouse you would be able to grow year around with the aquaponics. Trout and blue tilapia will tolerate cold water almost to freezing, with about 40 being optimal I think. Roughly. Bluegill and some perch will tolerate cold water. Catfish not so much, and pink tilapia not so much. I dont know other fish that tolerate cold water well that still grow well in it.
One could use a heater in the aquaponics tank in the winter or devise some sort of greenhouse to warm it as much as possible and have the heater as backup but warming a large volume of water will be costly I would think.
There are a few cold weather leaf plants that will grow in the cold. I am not sure if spinach will. Collard greens and turnips will. Brussel sprouts I think will and leeks will. Carrots probably will as mine grew last year in the winter.
Crayfish I dont know about but I have collected them in rivers that were in the 50s in temperature. Down toward freezing I dont know. There are some that are bigger than others. Thats about all I know other than they are good boiled with potatoes, corn, sausage, and some spices.