The Cokin system may certainly be a solution. They have the universal ring for fitting the X-Pro filters to non-standard lenses. A side benefit is that the filters can then be fitted, with appropriate adapter, to your other lenses. 104 sounds big, so you would need to check the max diameter this filter can support. They did just come out with an adapter that fits the Nikon 14-24, so it sounds like they can support super side angle lenses.