I would move the cycled filter from you 5g with all the fish & plants at 1 time, that will ensure their safety without needing to cycle the new larger tank as a separate issue. Just test ammonia etc for a while to make sure. It should be fine.
Yes, I know many want as heavily stocked tank with as many species as possible & you can find justification for it online. But the minimum of each of several species will not be as rewarding, interesting, or sustainable long term.
Ember tetras are tiny, they would be good as a larger group in your 5g once you get done adding more corys, neons & a gourami with QT to the new tank. Neons seem very mellow but they are tetras & may pick on smaller fish. Neons are twice as large as embers...both would be better in 8-10 groups & I think both with the guppies, gourami & corys would be too many fish.
Not to bash other posters on other forums but I noticed most had not much more than 1 year's experience...it can take most of a year for even small fish to reach adult size...& then what? Try to correct problems? Rehome fish? Just go slow & you won't have address that. It's always good to have a back up plan...