So, I started work a bit ago on a new tank:
20g long Truvu Plastic Aquarium.
I'm planning to put 3 Fire bellies in it.
I used black pond/waterfall foam for the background, with some cork bark.
Now I want to start on the land and water operation, but I'm not sure how I should do it. I want to have at least one terrestrial plant and maybe some aquatic ones if possible. I have 2 ideas:

1. Basic sloping gravel with dirt on top. My concerns with this is I feel without something holding it together it will fall apart into the water. I read somewhere that you can use moss to give structural integrity to the soil and gravel below via the moss' roots, but I dont know how well that will work and which moss would be best.(Pillow perhaps?)

2. More pond/waterfall foam on the tank's bottom to create a separator between the planted area and the water area, complete with a sloping bank going into the water. I kinda like this idea more, since I think it'll look good and I'm 100% sure the soil won't get soggy this way. The planted side could even have it's own separate drainage layer.
I was also wondering what kind of filter and/or pump system would be best.
I'll add some pictures of the WIP soon. Thanks!