Reading about the dwarf project is amazing but daunting! Try this thread
http://www.tomatoville.com/showthread.php?t=19549
which describes the released dwarf varieties and even has links to the vendors who are selling them. The following are others vendor sources selling the dwarfs who happen to be Tomatoville members. I have had great experiences with both of these member vendors!
Heritage Tomato Seed
Tatianna's TOMATObase
ginny