I think this will be an awesome scape and you should post pics of your progress.
Willow moss for the mountains maybe?
Definately, im still scoping out some deals on craigslist for a 75g with stand thats with in my budget. For lighting im gonna use 2 par38 led's that will hang over the tank. Do u guys think thats enough light for the cuba? Not sure about the willow moss not familiar with mosses. I might just try a variety of mosses.