lol, I live in Australia, In Brisbane and I'm 13. Well, I could get dad to weld me a template for my tank to sit on, so it would have no chance of breaking. And yes, I am planning to silicon both together.
The filter is simple too, Its going to be a Big Sponge filter, but you won't see it because It will be in the stand attached to the tank.
Heres a pic.
The box which is attached to the filter is a pump
It uses gravity, the water is forced down into the filter and the pump shoots it out
I like the idea of the bridge, it means my fish could have some protection from the larger fish which couldn't fit in there, But i wouldn't make one that goes over the top of the fish tank, I would prefer to holes in the tank and having bits of pvc connecting them.