I'll post some pics of my setup this weekend. Its pretty much exactly what ya'll are thinking of.
I running four of those same canisters. Three of them don't have filters. Instead I have PVC
pipe running down the center and attached to the bottom of the canisters.
The pipe also has holes near the bottom for the water to go through. This allows me to fill the canister with bio/carbon or whatever. The water has to travel all the way to the bottom to continue through. This way its as much media as possible.