What's your budget? I'd recommend to go to a local vacuum shop to test out several different models. There are some excellent used canister machines out there that can be had for not much money. No sense in overpaying for a new machine unless you just want to buy something new.
Some great canister models that come to mind are the Electrolux Epic 6500SR (or similar model) that Barry mentioned above. I have this model at home and it is fairly lightweight and easy to maneuver around the house. Works just as well as the older metal tank canisters, but lighter in weight. I think there is an Aerus Electrolux store in San Diego so go check and see what they may have available.
