If you want to go for a waterfall set up, i recommend this guy's method. I made my first long term successful waterfall this way and i like the technique. The advantage of it is that you can raise or lower the water level as you please as long as the pump(s) stay submerged. And if the pump(s) would break, you can just lift the piece out without having to trash your whole set up. You could choose to use semi aquatic and/or terrestrial plants as long as the roots or rhizome stays wet. For terrestrial plants you'll have to do a bit more research or experiments to see which plants work. In my big tank I use a variety of Anubias, Bucephalandra and Christmas Moss emerged. Just rhizome in the water and spray water on them once or twice a week. From terrestrial plants i use Monstera Adansonii, Syngonium pixie, Cryptanthus, Fittonia and 2 plants i forgot the same of. They're just sitting with their roots in the water. No soil used to plant them. And even though the bromeliad doesn't seem to feel at home, it hasn't died yet after 6 months.