I think for a 6.6 gal that this would be overstocking. Neons in spite of being small need room to swim, and male dwarf gouramis can get up to 2.5 inches. They are also in general very peaceful but they are territorial and need some space in the tank to themselves. So it's possible your gourami might get frustrated and harass and stress the Neons to death.
They both recommended to need at least 10 gallons or larger. I would go with larger, 15-20 gals for 8 Neons and a Dwarf.
For a 6.6 I'd add a betta, a couple plants, a pretty Nerite snail, and a few shrimp.