I would LOVE to have a mod where there was at least one, if not more, giant eagle that you could ride and own. What I was thinking was of just copying Odhaving character in the Creation Kit, changing out an eagle mesh for the dragon mesh, get some good sounds to go with it, and viola there you have a giant eagle you can ride. Is that possible?

Probably, but I have no understanding of your reasoning behind it. Good luck meshing and texturing a giant eagle. If it doesn't have precise details it'll look crappy, and I'd imagine feathers are a pain to texture.

Perhaps you can make do with the mod "Behemoth The Feathered Dragon" (search Nexus) i.e. Odahviing replacer as dragon with feathers.