I just put 9 emerald cats in my tank on Saturday and already they have uprooted all but one of my red Ludwigia
stems. I haven't gotten around to replanting them yet. These guys are 1.5" so I can imagine that a pleco could do worse. They are big and probably just knock the plants out of the bottom.
For plants I would suggest going with some substrate rooted ones, they will have to most holding power due to a more extensive root system, amazon swords , dwarf amazon swords , crypts and the like.
If you keep stems tight to a wall they might be more out of harms way and they are good backdrop plants anyway with the height. Fastest growing, for me in lower light, are the Dwarf Hygrophila
. They seem to put down decent roots fairly quickly too. Ludwigia
don't seem to root up so much so they will pop out easily. Java Fern
you can tie to rocks and wood so it is a out of immediate range of the pleco... and being tied down and hardy will stay put well enough.
Another thing that can help, plant immediately beside decor, rocks, wood or whatever you use, as the pleco will scoot past this and might not bump the plants. I really don't think that they uproot plants for the sake of uprooting them, maybe they do, but I would think that it is more incidental damage due to their size and activity.
Go with the sand BUT if you are concerned with dust clouds in the water, rinse it REALLY well. When you think that you have rinsed it enough, do it again. I've stirred up my sand and even picked it up from the front and dumped it in the rear and there are zero clouds of dust. It might as well just be small gravel at that point as all the silt and dust is gone. This keeps it from compacting at the depths that we might have in an aquarium too. When you put it in, put 4" at the rear for the stems to be planted into, the more depth, the better odds of their roots taking hold and, meanwhile, they are held in place a bit better.
Plants are great for so many reasons that they are ALWAYS worth any effort. If something doesn't work, try something else. I have 12 varieties in my 37 gallon tank for this reason, I figured SOMETHING has got to work. I've only had two of the original 14 species that didn't.