I've read in several books that it is possible (although, not reccomended) to keep clams under PC lighting if you feed them regularly. Squamosa, Hippopus and Derasa can do better under lower light, as llockke mentions. However, these would outgrow a 10gal pretty quickly.
Edit: You may want to try a Maxima near the surface, with regular feeding. Be prepared to upgrade the lighting, or give it away if it starts to do poorly.