Walmart ,Kmart,Lowes,Pamida,Home Depot, any type like these and your local nursery > In your area if they are not out yet they will be soon .
you also could grow from seed if you choose

gm319, do you want to buy plants somewhere near you, have them shipped to you, or what?

First of all, ask at all the nearby garden centers.

Most of the big box stores (WM, Lowe's, Home Depot) stock tomato seedlings from Bonnie Plants. There will be a few heirlooms among them. [Our weather's been so warm that I bought a couple of Husky Cherry Red last month and planted them already.] Here's Bonnie's tomato page; I've only seen 15-20 varieties where I am, and some varieties are only shipped to certain regions.
http://bonnieplants.com/products/vegetables/tomato-varieties

Have you tried asking at your local GW forum?
http://forums.gardenweb.com/forums/vagard/

If you'd like to go to Raleigh, you can buy a wide selection of seedlings from Craig LeHouillier, who occasionally posts on this forum. I'm sure there's somewhere on his site that says exactly which market he sells from.
http://nctomatoman.weebly.com/from-the-vine---2012-plants.html

There used to be another NC member who sold tomatoes at a farmer's market in one of the metropolitan areas downstate, but I don't remember his user-name or where he is.

You can mail-order from Darrel Jones of Selected Plants and have them shipped to you; I've never bought from him, but he's highly spoken of (and posts here). I believe he also has a wide selection of varieties.
http://www.selectedplants.com/