it's not really needed as long as you have a good turn over rate and some serface disruption to oxygenate the water. Of course all of my tanks have air powered hydro5 sponge filters in them so I don't exactly follow my own advice.
Go with an air pump and an air stone or wand. If you want to get smaller bubbles go with a limewood bubbler (like an air stone). You want it to break the surface tension not just move it.