Gouramis are also fairly aggressive fish and would not house a betta and gourami together. Years ago I kept gourami in a semi-agressive 90 gallon, and they insisted upon picking a fight with every other single member of the tank before they eventually settled in. And by settled I mean they either had their fins handed to them, or they harassed the other fish because it was not as big/mean until it would cower under a rock and either never come out, or killed it. Gouramis, from my experience at least, must always have a clear pecking order in a tank. A betta and a gourami would never reach an 'agreement' so to say on who is the meaner, more dominant fish (the gourami is faster than the betta, and the betta just isn't going to like the gourami's presence, period) and one of them would end up dead. Betting on the betta being the on dead unfortunately, since he will be the slower moving fish, although the gourami will probably have a few holes in him.
Current Quarantine Roll-Call:
Copper-lavender DT found in a tank with an adult VT male, apparently they thought because of his size, he was female and it was okay to house them together? Badly shredded fins.
Don't you just love what you can find in local stores?