The grains per gallon is one measurement method for GH (general hardness) and it basically equates to dGH, so 9.2 g/g is 9 dGH which is moderately hard at the low end so you are in good shape for fish. Those mentioned are soft to moderately hard water preferring so you shouldn't have much trouble. The tank is 67 US gallons with those measurements (I've assumed they are in inches, not cm, as you're in the US).
To the numbers. Corys are always better the more there are, so I would have no less than a dozen, and you could double that if you like. Try to get several of a species, all of them, or you can mix species but just have 5-6 minimum of each species if you do. Sand is perfect, and plants are good. Some chunks of wood will also benefit corys.
The tetra and rasbora are also shoaling fish, and again the more the better. With the space you have, I would not get less than nine of whichever species, some maybe 12-15, and you could easily have those mentioned. My only caution would be the Silvertip...with sedate fish (gourami) they have been known to get a bit nippy; if this were me, and you stay with gourami, I would find another tetra.
Honey Gourami are nice in a small group; try to get more females than males if you can; so one male and two females, or two males and three or four females.
Some floating plants will benefit all these fish, and the gourami in particular.
Do some water changes to lower the nitrates before adding fish.
Byron.