I would have to agree with dwarfs with regard to dwarf gouramis being un-healthy. I have had 3 red and blue neon gouramis which have all died due to what I now beleive to be bacterial infections. My female dwarf gourami has a ulcer on her head (bacterial) and I think that the rest of my tank is now infected (currently treating).
I have lost lots of fish now so I won't be buying any more dwarf gouramis. Instead I think I would prefer a dwarf cichlid like a krib as these are also very colourful and go well in a community tank.
Si