The seed companies in Australia have seeds for a Jap pumpkin which I think is the one available in the supermarkets. You can import pumpkin and squash seed from overseas, as long as the botanical name is on the packet. See Rays thread on importing seeds. I would look at some of the US websites, as they have pictures of the vegetable and you can identify them.

Was thinking of you just yesterday when I sorted out my tomato seeds and trying to decide which tomatoes to grow this year.
Hope all is well with you and you'll have a great growing season!