Welcome Atrain. Selecting a fish is really a personal selection of what appeals to you. Certainly you should only consider a fish that is appropriate for your tank. In other words, don' get one that would grow to be too big for your tank. And of course some fish are not friendly towards others should be avoided, unless all the others fall into that category and they can hold their own. You should probably also find out what they will eat and if you are willing to go the extra mile on an ongoing basis for those that have special requirements. For example, mandarin gobies are really fasinating, but they can be finicky eaters and they have special diets and need a well established tank.
I have a book that categorizes fish by their temperment, even gives suggested stocking based on size of your tank, so I am guessing there are many other resources that do the same.
I have never had a black foot clown so I cannot make any specific recommendations, but there are probably others on here that have.
Kerry