That tank is good for fish that are no bigger than 15-17 inch fish. You ould have a ton of mid sized fish in that tank. a 8 ft 300 gallon gives you more options on big fish. That tank gives you more options and more mid sized fish. If I had to chose between an 8 ft 300 gallon and that I would choose the 8 footer.
that tank is probibly about 18 inches in depth.