Betta barracks. Lots of 'em. I'm talking like four foot long, 2 foot high. :P With holes in the glass to let water pass through and one big heater that would somehow be adequate. lol
In addition to those barracks... a jungle-y theme inside- with white sand, lots of java moss, madagascar lace plants, driftwood, fancy rock formations, log caves, and those awesome light systems that simulate natural lighting- from dawn to dusk, etc.
In the hobby for 9 years.