Part of my issue is space. If I were to get a square shaped tank, it would have to sit on the floor. I have my current (empty) tank on top of my desk, it's just small enough to fit on the top shelf. Something square wouldn't quite work. Unless, I were to put it on the floor and then my dog might get in it...

Maybe I'll switch to plan B and get a Firebelly. They fit in a ten gallon just fine.