well.... every fish is an individual. some gourami species are more aggressive than others. the dwarfs are supposedly more timid and tolerant, but you may have the exception to the rule swimming around in your tank.
could they get along? maybe.
would i risk it? no.
at least not with a male betta. however, we currently have not one but two tanks with a gourami (one blue, one neon dwarf) coexisting with a female betta. in the 20g, ralph kramden and sexy girl coexist happily, and i have even seen him defending her from strange new fish. in our 10g, oatmeal and girlfriend don't seem to particularly like each other, but tolerate each other really well. they don't get into nip-fests... the most aggression i've seen out of either of them is a staring contest during feeding time.
so basically, if you must, you can try putting a little blue female betta in there. but watch everyone like a hawk. there may be a little chasing, because gouramis tend to do that to all new fish, but eventually the betta should be able to find a place to hide unti the gourami is comfortable with her presence. if there is any vicious nipping going on, or if she's still hiding after about a week, take her out and forget it.
