I think that fatboy could help you out more on this than I can, but I believe that www.airplants.com is a good place to start. the plant that I was holding openned all the seed pods a couple of weeks ago, liberating thousands of seeds into the air. I could try to see if I can get a few to you, but I know for a fact that it's gonna be years before you'll have a 1 ft diameter tillandsia like this.
Jœl
Jœl