There are loads of gouramis but my favourite Gourami has to be the Snakeskin Gourami.
There is simply no other fish that matches their personality. And while they may not have a lot of colour, they are fantastic uncommon gourami. And it can be kept singly. It is one of the most peaceful gourami species out there, they are not bullys like Pearl, Opaline (blue, gold, moonlight) and Dwarf Gourami can be.
Carl
my lfs has snakeskins in stock at the moment, and they can be kept singly? thats interesting
all gouramis can be kept singly. its a common misconception that they should be in groups. in fact, i think they're much better off singly unless you have a strong desire to breed them. gouramis generally just don't like eachother. lots of chasing, lots of nipping, no love. and they definitely don't gain any sense of security by being with other members of their species.
my understanding is that even in the wild most gourami species would never pal around in schools or even pairs... they are essentially solitary fish.
for the size tank you have a snakeskin gourami is the perfect centerpiece. they can get up to 8 inches and despite their size they're significantly less aggressive than other gouramis. the fact that your lfs actually has them in stock is even better, they really aren't that common. i say go for it.