Well frankly, if the Discus doesn't make observers go 'wow', I don't see how any other additions can!
I strongly urge you to do as much research on these guys as you can. Use google, buy a book... but these basic quesions are something you should know if you plan on keeping them. The forum is best to discuss the finer points. Once you research you'll find that if you have three and two pair off, the third will probably get beaten. You'll find they are best as a compatible pair or a decent sized group. They are not outwardly aggressive, but can be amongst themselves. They are also very finicky about water quality, so understocking is a must. Go with just one species of shoaling fish and give them a decent group. Do the same for the bottom dwellers. As far as the 'wow factor' is concerned, stocking in this manner has a greater effect anyway. Make sure your stocking levels and your maintenance routine result in pristine water. They do not tolerate the nitrates that most tropicals do.