how come just those two? no moss or buce or bolbitis?
well, I think one of the first questions to ask would be which species of anubias, because there is quiet some size variety in that genus.
secondly, I'd think about what kind of fish I want to go in there as well, since larger fish means different hardscape placement, which would mean a different method of how you would have to layout the plants onto the hardscape.
once I have that kind of stuff figured out, I guess I would then setup the tank in such a way where there is intricate hardscape intercrossing throughout the tank, with some larger pieces of hardscape being solid and covered in plant life. Then, I would try and decided, based upon your hardscape, how to layout the different species and varieties.
I would also try and avoid anubias varieties/species that look too similar to each other, especially because of how slowly everything in this tank would grow and because of how it is easy to lose sight of minor differences in a large tank with a ton of similar looking plants.
Also, I would splurge and get some of that white anubias, because why not?
check out "therick2325" on youtube. if i were to do a tank like that it would look very similar. some long branchy dw for the JF to spread on would look cool. i would probably add some big coffeefolia and congresis
Just curious, why? With the scape you describe the moss will add a softer, lush feel to many areas. Actually if you look at my flickr the first pic, I think is a 'large' tank with mostly ferns and moss. Sorry no anubias
My current scape could go all Anbias and Java fern, look at it - link in my signature. I would use a light colored sand with a pile of rocks on it with a pile of wood on that on a fern/Anubias scape. I would use wood with some heft to it, twigs don't look like they can hold up plants for long. Anubias fits in the crevices of the rocks and the ferns grow over it. With a good sized tank like yours the Narrow Leaved JF or the usual broad leaved form would be fine and you could add Trident or Windelow if you like the looks. The normal JF plus Trident JF plus A. nana might be enough variation in texture for you. Look through the ADA videos, there are lots of tanks like this in the ADA gallery.
I have a bit of Anubias that looks like it is going to grow out over the substrate, that would something to encourage. Plan lots of crevices for the ferns and Anubias to lodge in, gluing or tying to the middle of a branch looks less likely. I don't have much moss in the tank currently but it is easy enough to add later if you happen to see a tank with it that inspires you.
My corydoras and platies seem to think the biggest Anubias is a love shack, wonder what it looks like inside? Under the tangle of wood is a great place for my wood loving bristlenose plecos to hide out in, a pair of dwarf cichlids or a tangle of Kuhli loaches would love it too. All those Java fern roots have to be a good hideout for fry. I planned windows in the wood so the fish can swim through, even the Congo Tetras take advantage of the largest one. My corydoras are fine with my ground covers but would adore having sand to root about in. I would definitely want either corydoras or Kuhli loaches or both in such a tank. Cherry barbs or Emperor Tetras aren't schoolers but interesting fish I might want or just go with one of the typical schooling fish.
I have about 2 dozen sticks of manzanita wood that I placed on top of the rocks to make windows and spots to wedge the plants into. I looked at them and decided where the breaks were and worked on each bunch as separate arrangements. Picked them up and screwed together with stainless steel screws and attached each bunch to a bit of acrylic sheet that is anchored under substrate so it stays where I put it.
I mostly just wedged the plants into place but some of the plants were tied to pebbles then placed. Tiny plants were glued with super gel glue. Just read here about an even easier way to weigh plants down, just put some super gel glue on the bottom and dip in gravel.
There are plenty of amazing tanks with Java Fern and Anubias only. Well, and some driftwood. The only thing that is important is having a foreground. It could be a plant, it could be sand. It doesn't look great to me when it's got a lot of even colored substrate just hanging out in front.
How would I go about it??? Get very interesting wood or make not so interesting wood look interesting by arranging a lot of it. As said, figure out some sort of foreground/separation from the front to back. Then plant accordingly. It's a great combo, I agree with others to not count out other plants but it does work alone, or with one foreground plant.