So the plan is to change the substrate to sand, and have 5 Kuhli loaches, three Honey Gourami, and 7 neon tetra. You could add a group of another smallish peaceful fish, like a species of rasbora, or some of the tetras. You won't see too much of the kuhlii loaches, they are fairly secretive and nocturnal.
At this point, we know soft water species which is relatively easy. But you also need to keep in mind the temperature...neons do not like it very warm, compared to some fish, and the gourami and loaches here are Ok with a temperature around 75-76F (23-24 C) which the neons prefer.