Yeah, I agree with JWT. Exceptions keep things interesting (like my way overstocked FOWLR,) but they just that; exceptions.
Many people have a preference to what they'd like to keep. In my case, it was a really neat looking green wrasse (Thalassoma lunare.) Once you have a preference, learn all you can about the fish(es.) Then you'll be able to make a plan based on what you know about fav critter(s.) My fish required swimming room, was an agressive feeder, hated any fish that resembled it (especially shape,) and could be a sh*thead to fish that come after it's established. Now I have a real cool collection (19 months now) that includes several species that I would never have just 'picked.' Like a Foxface. And it includes others I have always liked, such as a Picasso trigger (R. aculeatus.)
Plus you can eliminate species by learning as much as you can about them. If a butterfly you fancy subsists on coral polyps, you may want to dismiss it and keep looking! In the end you'll have a healthy group and a database of knowledge to boot!
>>{{{~}}"> YBYW