the lady at the LFS told me that it would do better alone than with another gourami. I have had two gourami before that seemed fine together. Should I get another one or will it truly do better as the only gourami in my tank?
It would help to know the tank size. And confirmation of the species as Trichogaster labiosa. If the latter is it, it is one of the more peaceful gourami, though individuals can vary. SF says it is fine in a small group if purchased young. Older fish may have more "personality" obviously. Two or three males would be bad, as DD noted.
Given that this species attains 4 inches, a 30g would not provide much room for a group, so i would stay with the single fish if you really want this species. Or consider another peaceful gourami species, there are several.