Hydroponic clay balls will do very well as a plant medium in that pot to hold the plants upright and they will also store nutrients for the plants in time due to the cation exchange capacity of the clay balls.
I have several emersed plants in one tank: peace lily, Antherium lily, spider plant, mini parlour palm, also pothos will work. There are many more really you can choose from.
The ones I mentioned don't need much humidity on their leaves so no need to worry about spraying and such, and adapt to having their roots in water very well. Their roots are fine in the water with the fish.
Are you hooking up the powerhead so flow runs through the pot like a trickle filter? If that's the idea, make sure there's a good outlet/hole for the flow to drain into the tank as these little holes may get clogged in time and the water will start falling down the back of the tank instead one day(been there, done that, lol)
What I'd do instead, is bigger holes, more holes so plants just have access to the tank water without additional flow inside the planter(safer), and their roots will eventually find their way outside the pot and have easy access to the tank water.
However, if you really want the plants to mop up enough nutrients from the water you may need some proper light over the plants as they won't do well, except the pothos, in room light only, unless they have good access to day light.
A cheap power led like water resistant flood lights in 6500k will do.
Good luck and please post pictures when done
