Moss mosses will do. Java moss, Christmas moss, flame moss, etc. In order to get the "wall effect" you will need some wire grid or almost like screen material with holes large enough for the plant to pass through and grow on, in, and around. Spread the moss in a fine layer on your substrate. Ley the grid material on top of it and gently pull through what you can so some of the strands are still under the screen. Within a week or two you should be able to move this material and stand it up where you want provided that you have strong enough light to rapidly grow the moss. Most mosses will grow in the lowest light conditions but they will grow faster in higher light. Cut the size mesh you need and you should be good to go.
You can also attach the moss to the driftwood and tie it with fishing line or string and it will grow into the driftwood. I thought you might want more of a "wall" for the background and that's why I suggested what I did above.
