TY! I want more! MORE MORE.. I wanna build a huge Plywood or concrete tank and simulate a Rift Lake Reef. Still in dreaming stages though.. 
Very nice setups. There are fibreglass tanks with just a front viewing panel that are cheaper than very large glass or plastic tanks.
Yes that link is the type im thinking of. But they are availble in much bigger sizes. Basically a giant box with a viewing panel. Im not sure if they reach 500 gallons but they do reach a few hundred i think