do not mix gourami with barbs, those long trailing front fins will be nipped off in no time.
what is your tank size and filtration? this will determin some species you definately wont be able to keep. for example, rainbow and red tailed black sharks are 1 per tank and need at least a 4ft tank.
to start with you really need to bulk out the schools of barbs though, its not fair to keep them in such small amounts. they need 6 or more to a group and this should be considered minimum. you can mix different types of tiger barbs though, so maybe try 2 normal, 2 green and 2 albino to create your group of 6. then add another 4 gold barbs. after this, it depends how large your tank is as to whether you will be able to add any other types of fish.
if your tank is large enough then you can add a few platys, or even mollys if the tank is large as they can reach 4" long. 1 male to 2-3 females would be best, the fry will easily be picked off by the other fish if they do breed.