I suspect it's a platinum gourami. This is a color variation of the Trichogaster trichopterus aka the blue three spot or opaline gouramis. They are very beautiful. When they flare they often show pale shades of pink or blue or sometimes yellow.
No, gouramis do quite well alone. Females are much more sedate than the males and if several of them are kept together will often swim together almost like a school. Adult males, however, can get fairly aggressive with the females and even with their other tankmates.
This is the mother of the three gouramis I posted above. She is hiding from the male who she spawned with several times. Interestingly enough, when I set her up in a spawning tank and added the male, she took over and he politely built the bubble nest to her specifications.