Sounds like a good plan, Dave. I'm not familiar with the weather conditions where you live, but from what I've read elsewhere on this forum you might need to be careful regarding temperature (especially in winter) - pots (even a whiskey barrel) are more susceptible to temperature variations than a garden bed.
I've got some single-colour viola/pansy seeds to plant once I get the lilium bulbs in, so that should complement them nicely (white pansies for the colourful liliums, apricot violas for the white "Navona").
