If putting it in a basement that should work out for you. But you still will need to be sure the floor could hold the wieght. It the basement isn't finished the concrete could crack and cummble from the weight. and if it is finished, sometimes they use 1x2 on the floor over the concrete and put plywood then flooring or carpeting over it. I am just saying thay much wieght concentrated on such a small area, you need to be sure that it will be properly supported.
Have you given any thought as to what type of tank you want this to be.
A tank of this type will be very tall. Probly at least 36 inches, but I would not be surprised if it isn't quite a bit more.
If you would decide to do a reef. You lighting would have to be very strong to penatrate that much water. I don't believe a 400 watt MH would work. So you would be haveing to find something much stronger to reach corals towards the bottom of the tank.
Also there is the fish issue. You hear people on here say that tangs belong in a 180gal tank or larger, They are talking about standard 180 tanks, Six foot tanks, Tang need lots of swimming room. and swimming up in a circle is not the best idea. The same is true with alot of your bigger fish. Because the fact is, Is this would still be a 3 or 4 foot tank, The only plus is you could have alot more smaller fish.
I realize that you haven't said anything about a tang, or a reef, or about any of the fish you would like to keep. I just want you to be aware of want you are in fact getting yourself into with these circular tanks. They look great but there are problems and limatations with these.