Hi,
10g is still pretty tiny...a clip on LED or a small T5HO would be the best thing, in a 10g tank it won't take much. Lots of soft corals don't require all that much light. Mushrooms would grow under regular fish lighting, as well as Red Chili coral...Kenya tree coral, Xenia and leathers would be happy with T5HO or LED. There are also all kinds of non-photosynthetic corals that are truly beautiful, they wouldn't need anything special as far as lighting, just really good flow and lots of food...be prepared to do water changes often, since a 10g won't be very easy to keep stable.