Here's the most comprehensive list out there, complete with hotlinks to sites.

Here is a link that might be useful: Dahlia vendors

Hilltop does cuttings.

Thanks, so does Aztec. There was just a couple of plants that only Corralitos has that I can't get anywhere else.

Which Corralitos dahlias are you looking for? I know the feeling...I lost my Summer Rain and was planning to replace it!
I did have a lot of Corralitos dahlias last year and have dug all my tubers. And if anyone has a Summer Rain tuber extra please let me know!

Good to hear you will be growing dahlias this year pdshop.