Mixing clowns is not a good idea, often they will fight to the death. There's probably not enough room in your tank for them to have distinct territories. You'd be best off to trade in the one you have now or skip getting the percs.
Do not mix tomato clowns with perculas. I tried it and the tomato was really aggressive towards the perculas. Either have one or the other, but I would not suggest both.
Carrie <img src="graemlins//angel.gif" border="0" alt="[angel]" />