I have not seen the larger leaved, parent variety in any of the garden centers over the last 4 years we have been here.
Most offer the newer, dwarf variety, which I have used. The dwarf variety is touted to be 'improved' over the original, but I don't know if that refers to improvement in color, disease resistance or what, exactly.
The biggest downside is snails- they love the stuff.
I find they are a little tender during the winter and benefit from protection.
If you have never tried Dave's Garden (online) you may have some luck pinpointing the name of the particular variety you are looking for, along with pictures and information provided by real gardeners.
Type in Oyster Plant and go from there. Often there are links to reliable mail order sources.
I've had good luck finding particular plants and bulbs through their site.
Of course, you might also ask a neighborhood gardener here if they would share a bit of theirs with you. Having their garden admired often prompts an offer of that kind and they may be grateful to have an opportunity to thin out a bed!
I'd wait until the last frost date however, no matter what you do. (March 15th.)
Happy Planting
