You might consider the prefab insulated wall panels.
If not I personally have thought about using the metal studs. you can get plastic in 4x8 sheets for a bit of wainscot or stainless.
Also, there are a few discussions on using a airconditioner- I think you will need a digital controller but they are fairly inexpensive.
I think up high is fine- you can always duct it down low.
Also you need a way to control humidity.
Last edited by KRAKMT; 01/25/20.
