Hey there Daniela,
I assume you want some smaller plants then for the foreground. The Anubias Var. Nana is a great plant, it's small, it's a slow grower and doesn't need a lot of light. You can't bury the rhizome but you can tie it to driftwood, rocks or whatever you've got in there and it will grow. But as far as other low light plants that will stay smallish for the front, I'm out of ideas.
Other low light plants that do get a bit larger: Java fern, Anubias, Anacharis, Hornwort, Most Mosses, Water Wisteria and that's all I can think of.
I'm not sure the lighting requirement for Wendtii but I love mine and they're pretty cute, they don't grow very tall. There's also an Amazon Sword Rosette, which is a very small sword that grows a stalk and then new plants come off of those and can be picked when ready.
But I think that's all for now :D