Like I said, two clowns max. they should be male/female of the same species. Introducing a third would cause some agression issues. You have lots of other choices for fish. It will depend if you want corals in the future. For now, dwarf angels are nice...flames or coral beauties, or a lemonpeel. royal grama, purple firefish or some type of wrasse (like a sixline) would also be nice.
Some people are like slinkies...they serve no real purpose yet can still bring a smile to your face when you push them down the stairs!:p
Have a great day! Brian