This is a response from a friend of mine yhat does breed clowns. His response was to the same type question.
Robin here**... Hey Charles, if you do want to mix species I'd stay in the perc / occy complex as they tend to match better. Even better is to get one of the occy variants that has the color you want since you're still dealing with the same species even though the fish looks different.If your female is in the 1.5" - 1.75" range then I'd get a male that is visibly smaller, but not tiny (nothing less than 1.25"). The size difference will help to ensure dominance, but the min size will help ensure that the new one doesn't get totally beat up.*Also, keep in mind that fish do have personalities, and within the same species you'll find ones that are more chill and others that don't want no-one coming into their territory. I don't know the personality of your female, but if the space is relatively small and she's been in there awhile, you may have to deal with territory issues if she's not one of the relaxed ones. If you've been thinking of doing any tank decor adjustments, perhaps do that at the same time you add the new male (post QT, of course!) since that may shake things up a bit and she won't be quite as defensive to the newcomer since she'll be distracted trying to figure out who rearranged the living room.Good luck!*