The seller "gostatue" on eBay has a lot of face molds. Some of us at DavesGarden used them along with a clay pot to make planters. I'd suggest looking at them at DG in the concrete forum for ideas. I've bought a lot of molds from gostatue and find her very good to deal with. With a mold for $10 or so and a clay pot you can get started and do a lot of playing for very little investment.
I'm new here at ATP but saw this thread and decided to contribute what I can. katie