One idea I had for background plants was Riccia and Eleocharis Acicularis, using E. Acicularis in the extreme back kind of interweaved with Riccia.
Love the light, maybe you can show us how did you made it
Thanks! I should have photo documented it. It was pretty simple, with a basic knowledge of LED's and some soldering skill. Really the hardest part was deciding exactly what to get (PM me for details). It didn't cost more than $100.
The only thing I could recommend is moving the smaller stones to the front and the larger stones to the back. Otherwise, your expensive stones will be hidden.
Thanks! I may have to raise those smaller stones as my carpet grows, but I like the perspective they give to the tank.