Yeah, I agree.
When I first decided to make a large indoor pen, I just rearranged the furniture a bit.
At one point I had the pen halfway under a large buffet table to take up less room...

As for aquariums...yeah, they are a pain trying to find room. I'd suggest buying a shelving unit for them...you can usually find a cheap, but strong plastic fit-together shelf from most hardware stores.

As for the tote...yeah...large 50 gallon rubbermaids totes...but again, I'd only suggest that for short term keeping. Bigger is always better.