Try Pinetree Gardens -- they have some in their online catalog. I've used them before. Their seeds are of good quality, relatively small packets and priced low. Something to look for, but maybe not this year, is Cramer's Knee High variety -- it's shorter than normal, but denser and earlier than average. However, Johnny's, my source in past years, says they had a crop failure for this year.

Here is a link that might be useful: Pinetree Gardens