How would I make a Bin cage topper?

[rockstar11p]

So Sonny's 10 gallon cage is way too small, so I was gonna make him a bin cage but I decided I would try to make bin cage topper on top of his existing cage so I can still keep it on my dresser and have a decent view of him at least some times. I was thinking about putting a small bin a little larger than the actual aquarium on top of the tank and cut a hole in the bottom to connect it using a plastic crittertrail tube. I was actually looking into buying a cage topper, but the only ones I could fine are wired, and take up more space than they provide. It's usually like two small platforms while this would be an entire additional floor. I could put bedding in there without worrying about it falling through to the bottom and getting in his food. I was probably going to connect the water bottle by drilling a hole an connecting it. Any other ideas? The only thing I'm worried about if the somehow the bin gets pushed off the tank because the two aren't connecting. Is there anything I can do to temporarily connect them without having to glue them together. I want to be able to separate them when cleaning. Any other ideas? I would like to incorperate the tank because I have no where to put it, and hate to see it go to waste. Thanks for all the help :)

Also, How many holes should I drill? Will there be enough air in the tank since the only air getting in and out is from the tube? Should I put more than one in there?