Hi GotCrabs,
Good idea on ur tank and natural plant soil..........
I also have an idea similar to yours, the tank will be a Juwel Korallux 60 54L aquarium. With natural live clay gravel similar to yours, plants such as elodea, jungle val, anubias, and a carpeted tank bottom, tank is a 54L si i will have plenty room, it will also have small shrimp, endler guppies (maybe), and some other small fish species