Love it. I really wanna see more pics of how the refugium turned out, even if you end up using your fluval 204. Like STS_100 said, it's looking sexy.
As for your scape, I think it's great. Don't add anything on the right. You said you were going for the iwagumi look, so you've gotta resist that urge to "balance" your layout into something expected!
Question: What's with the second mini light on the ref.? I think it's rad, but what's it's purpose?