That's looks awesome! A fellow hobbyist in Minneapolis built a 4' X 8' X 4' tank (he was trying to save on lumber) and kept altums angels and discus in it. He used garden soil and planted it heavily. It had dozens of corys, hundreds of tetras and all sorts of dwarf cichlids as well.
He had to reinforce the tank, which started to bow out, with screws and steel wire at the top.
Good luck with this and post some videos, Willie