Do the fishless cycle.
That way, whatever amount of bacteria came in with the plants will grow to the maximum amount you could want, to handle the waste from any reasonable amount of fish.
It does not matter whether the plants or bacteria remove the nitrogen, just so long as something does. But you will not know how good a bio filter you have unless you add ammonia.
You can do it with rotting fish food, if you want, but ammonia is easier, and you know exactly how much you are adding.