That is very striking! And the matching points looks perfect. Definitely a border to frame it, like a picture. The dark gray could work, but my first thought was a darker brown. I use Hobbs 80/20 and it's a nice weight for wallhangings, not puffy. If you don't wash it (I don't wash my wallhangings), it will stay fairly flat? I have no advice on hanging it as I lazily just use clear push pins!