I would not try keeping a male with female betta's. You will have carnage on your hands. The females would be fine, or the male, but the combination of the 4 together would not end well. Breeding wouldn't be the issue, they would probably kill each other first.
Well if I keep the gouramis and elimate the betta, what other fishes could I add? Another school of cardinal tetras or would the bioload be too much then? Any suggestions would be appreciated.
Also the malyasian trumphet snail...should I introduced it to my tank at some point for the burrowiing and the algae eating or do I already have enough bottom feeders. I'm aware the MTS breed like rabbits but I'm doing it for the plants...right?!