Type of clay?

[shadowshow.livejournal.com]

I was just honored with the task of hand sculpting my best friend's wedding cake toppers (in the shape of puffins!). The problem? I have no sculpting experience and no idea what clay would work best for such a project. I know I can replicate puffins if I have the right materials!

Would someone be kind enough to tell me what type of clay might work best for wedding cake toppers, about 4-5 inches tall?

Thanks so much in advance...