Baker Creek Heirloom Seeds http://www.rareseeds.com/
When I lived in Denver I had great luck each summer with squash bred from Cucurbita maxima...here they tend to do poorly for me. But my friend Allen Boatman has had great success with them at the gardens at the Falkenburg Jail.
Seminole Pumpkin is a C. moschata native to the Everglades and has done well for me, as has 'La Primera' (bred in Florida for Florida) and Japanese kabocha (some feel it is C. maxima X C. moschata) plus 'Argonaut' a LONG squash. Even if you are not in Florida and you have hot muggy summers and warm nights, give some cultivars of C. moschata a try as they often have deep orange very flavorful flesh. Plus the young vine tips can be used in stir fry and the male blooms make lovely edible plate garnishes. Cultivars of C. moschata almost always have beautiful silvery markings on the leaves that some folks mistake for disease.