I'm interested in the over-all idea, and agree with the suggestions of both larger and smaller sizes.
I like the shape of the Superhawk. It's a less extreme hawkbill. But.. By decreasing the angle from the hilt a few degress, it would increase the cutting potential while maintaining an easier to sharpen edge.. And that would suit me well.. Hawkbills are a tough task for me, usually..
As far as steels go, I'd want something tough, with an edge that lasts (duh :p ). I want edge retention in this. I'm not a steel nut though, so I don't really know what would be ideal.. I do know I love my M390 Millie and PM2.. So that's what I'm gonna go with. :)
But, I'd never go for FRN. I don't like it, never will. I don't say that to instigate anything, btw. It's just my own personal quirk.. One of many :)
Micarta, G10, wood.. Anything but FRN. It just feels like I'm holding.. nothing. Too light. Again, that's just my own personal preference.
I'm all-in for a 'HawkMule'. Fantastic idea
Edit--
Forgot my suggestions for potential names:
-Peregrine (for a smaller version) (these birds are amazing!)
-Golden Eagle (for the larger one) (also, it would make more sense if it were made in Golden :) )