I cast the pools with concrete. Reinforced witht he wire fabric. Put 20 mil plastic down to keep concrete from leaking. I painted with fiberglass. Add some penetrations for drains and valve. You need to thicken up around penetrations or you have leaks. Use a wall sleeve if you can get one or fabric something to go around the pipe to prevent leaks there
I used 4x4 posts, I installed after I cast the pools. (it was a wing on another green house). I used 2X4 10 gauge wire on inside to serve as the cage. I used FRP on outside for sheathing. You will have to frame to make the fits. Draw up a set of plans to scale so you can think about things you need to.
Heater is climate driven. You may be looking at a pool heater or simular. I have 8 to 10 foot diam pools so submersible heaters would be difficult to heat that volume of water.
For the air, I would look at what the zoos use in your area to get an idea of the size. You are looking at something over 100,000 BTUs.
You got to think this out tho. My idiot brother wanted to heat a small green house. I said instll a gas heater. He called the gas company and they instaled 20,000 BTU heater (in VIrginia) --I use an 80,000 BTU in FL. Needless to say it didnt work. so you have to be sure about sizing.
You may be talking about quite an installation now.
Best regards,
Ed