Anubias does best in quite low light. Moss on the contrary has always done best for me in better light, near the surface somewhere in as much flow as possible. I've placed it over spraybars, other filter sponges or driftwood, etc...I can't tell about java fern. I killed every type I've tried. There's something in my water that makes it suffer slow but sure death although I've grown various way more difficult plants..
You can try crypts, once they root, the root system will be interconnected all over the tank underneath the sand. No fish can uproot them when established. They do really well in mature, older sand substrate without any root tabs.