The tank dimensions could work, you could even add a small group (6) of small, upper water "dithers" that are comfortable in the conditions Chaetostoma spp. need (10-20x real turnover with plenty of surface movement, 20-23C). A few options that spring to mind are Bloodfin Tetras (Aphyocharax anisitsi), WCMM, or Golden Pencilfish (Nannostomus beckfordi).
Pebbles, rocks and real/fake plants that can cope with such conditions will work, but I would be cautious about adding leaf litter and too much bogwood. Rubbernose Plecs are not very tolerant of organic matter in their water, leaves and wood will add various compounds including tannins.
These plecs are not vegetarian like BNs, they are omnivores with a meaty preference, in the wild they are often found on algae covered rocks because they are feeding on the tiny critters ("aufwuchs") that live in and around such rocks.
They are usually wild caught and are not easy to adapt to hobby food, I've lost two new purchases through starvation over four or so years, quarantining them to ensure they recognise hobby food is essential for a few weeks. New Era do some great Tropical Pellets and Plec Pellets, that are soft like plasticine, you can press these onto pebbles to help Chaetostoma adapt to captivity. Others try "painting food" onto pebbles, using egg white to bind crushed food and then letting it set dry for several days before adding to the tank.
My existing four (2 aff. milesi, 1 dorsale, 1 "mystery" species) now all readily recognise lose food (the New Era products and Tetra Prima) when it is added to the community tank.