the most common clownfish i have seen breed are wild pairs of percula clownfish. an anemone might increase their chance of breeding. but the thing with clowns is that they may breed in a month... or it could take a year... or it could take 10 years or they may never breed at all. you have to be very lucky for them to breed. and if they do breed u need a separate tank for the eggs. u need to remove the rock or whatever they have breed on around day 6, and place it into another tank. a 10 gal would work just fine, and u need rotifers. ur not supposed to have any filters just an air pump for oxygen. its very hard, u need special set ups for brine shrimp and phytoplankton. search some more on google.
good luck!