For a first tank, I would say that is one of the best layouts I have seen. It has amazing proportions and focal points. Kudos to you.
I have not worked with it (any plant for that matter haha), but I believe a lot of iwagumis use Vallisneria Nana. You could plant that on each side of your tank behind the rocks.
You are much too kind, Trenton. Thank you so much. I'm subscribed to your scape, as well. I know it will be amazing.