has lists of most major manufacturer filters with part numbers. Includes a K&N washable filter, but it's easily twice the price (or more) of the paper ones, and for clean air driving conditions the paper ones last a long time.
As far as I know the H1 diesels run the same setup as the military diesels for air filter (except the Alpha) so if it's designed for the H1 diesel it should work for the HMMWV if you're talking about changing to a different air intake and filter style.