Neons probably won't work great either. Nor will the betta on further thought - bettas are very slow swimmers, and will be totally stressed out by the FM and con, and cichlids and abanatoids don't seem to like each other very much to boot.
You already have a lot of colour with the liverbearers, do you need some tetras? If you do, I suggest serpae tetras or maybe some cherry or gold barbs. They're a little more robust than neons.
Oh, and be careful with the swordtails - I'm not an expert, but I believe they need some salt in the water to thrive (or very hard water), whereas the FM and bushynose plec won't like that.