I love that you have no fear on a project so large...also love that you are posting your ideas and asking questions. That's a sign of a very wise person. I plan to do a climate controlled greenhouse one of these days and can appreciate the "big idea".

I know you said you don't have the room in your current home for even a nano tank, but I do think it would be of a great benefit for you to take some time keeping corals in a less expensive environment to get the basics of this hobby down first before venturing into such a large project. What you learn from keeping small tanks will surely prove to be very helpful in your plans for the much larger projects and may be at the root of some new ideas for you.

welcome to MAAST too.