Just a warning. I have had a fairly steep learning curve trying to master the fisheye. It takes some work to handle it, especially with strobes. Strobe placement and avoiding backscatter isn't trivial (at least to me, who dive fairly murky water and was more familiar with mastering the short tele perspective than the super WA perspective topside).
At least for me, a superwide rectilinear WA was easier to handle than the fisheye. So it's possible that you, too,will have to work a bit before you're happy with what the fisheye can do for you.
You can see a few of my pics on Flickr; the link is in my signature.