I'm growing a moss wall with weeping moss at the moment exactly as Zozo described with a few java fern 'mini narrow' spread through it and it's working beautifully. Weeping definately grows more slowly compared to Java etc. but this is potentially a good thing as once the wall has filled in it should reduce trimming which, on a moss wall, is extremely messy. Already I have to pick out tiny shoots of weeping moss from all my other plants, no matter how hard you try you will always spread some around when you trim and with a faster growing species this will be obvious more quickly.
Weeping moss also begins to naturally cascade downward at a certain point of growth which makes for a much neater wall with more complete coverage.
I have found it important to trim very aggressively initially to encourage the dense branching that will fill out your wall.
I used a single dennerle tissue culture cup on a 53cm x 25cm plastic mesh and with trimming of new shoots to promote branching this proved to be plenty but it has taken about two months of pressurised co2 injection and daily fertilization to look like an actual moss wall as opposed to a plastic mesh with moss growing on it.
Other people have had different experiences with tissue culture cups but I also found that it took about a month to adapt to submerged growth and/or my water chemistry.
Good luck!