I love mosses too. I have several. I guess I'm partial to a mix of plants. I like the contrast you have between the rocks and the sand. 
I like your idea. I had considered watersprite for the corners. I like the African Water Fern and I have a 2.5 gallon that's over grown with Needle Leaf Java.It looks like a good base for moss tank.
My suggestion is to add some Microsorum Needle Leaf or Bolbitis heudelotii to rear corners of the tank.
That would look awesome for sure. I'm not sure I have enough light and the lack of CO2 might be a problem with those plants though.If it were me, I would make a steeper slope front to back and fill with Downoi and Blyxa around the rocks with something taller in the back, maybe Val nana.
Shipping USPS Flat Rate to Canada = $24.00 for packages maximum of 20lbs which is roughly what is pictured in that 10 gallon. $20.00 for the rock and I'll put together a package for you.Love the rocks. I wish I could find rocks liek that around my area (ontario canada)
I accidently deleted the photos from photobucket. I couldn't seem to edit the original post to delete the links.What happened to your pxs? Can you post some now?
You need the java fern v needle leaf. Shame you aren't near me for I have some I could spare.I'm looking for some taller java fern to fill in part of the background.
I am actually in Las Vegas. Thank you for the offer though.You need the java fern v needle leaf. Shame you aren't near me for I have some I could spare.
Your java fern look like they need some flourish excel or hydro peroxide and Calcium sulfide.
Are you in Canada? Where are you in Canada?
These 2 are in Canada:
Rusalka Toronto, ON, Canada
Sunstar Burlington, ON, Canada