I've got a few from heads I grew last year. What seeds would you like to trade?
I bought these originally from Gurney's. I think they have them this year as well. I've even seen the seeds at my co-op. You might try one locally and see what you can find.
PM me your address and I will mail some seeds off to you. I'll do the same and we'll see what happens.
My only worry is that corn is often a genetically altered hybrid. I don't know if you can plant seeds from non-heirloom corn that you have grown and have it turn out to be the same plant. I am happy to send you some seeds, but have no idea if the seeds will breed true.
You might also try Baker Creek Seeds (www.rareseeds.com). They have only heirloom seeds, so you can replant from your own harvest. I think they have an heirloom version of the strawberry popcorn.