Brian's Botanicals has some nice Cannas and they're a very reliable outfit. I agree they're easy to overwinter in damp peat, sand, soil, whatever. From a mail order they may not get huge in 2014 but the following year watch out. Big pots for sure, just not terra cotta. This is 'Phasion'/Tropicanna in a 24" dia. tc pot.
I had the pot in an oil drain pan but switched to a watering trough so I wouldn't have to fill it every couple of days. They get 6' here. City of Portland is my tallest at 8'+. It's pretty boring though. I've heard some strains of Stuttgart are more stable than others. Will try Brian next year. Does anyone grow Cleopatra?