I think Tom Cruise is too charismatic and affable to play Hawke. Hawke is a quiet reckloose-loner. The opposite of about everything we've seen Tom Cruise do. Josh Brolin or Josh Hartnett are good choices though!
I never would've thought to cast Samuel L. Jackson as Santini. But he is a great choice! I would've went with Robert Duvall, tho I think he would be too old to do it now.

Some pretty good choices, but since the chopper is the real star you wouldn't need big names, some hungry up and comers would do. Plus I would rather see a continuation than a remake. Have some distant relative of Santini or Archangel designing a new version of Airwolf, only to have it stolen by some evil Saudi billionaire who plans to mass produce it and give it to terrorists, so our hero puts together a team to steal it back, and fight their way out of enemy territory.