We are over on the Big Island but havent heard of any recent litters....there are some other folks from HI on the forums so they may know more. Another possibility is to do what we did and import a pup from New Zealand, they too are rabies-free and therefore there is no quarantine to worry about. Its a bit more expensive but not by much given the prices people charge for boxer pups on the islands. If you want info on the breeder we used, pm me as i dont think Im allowed to post it here. And Welcome to the forum!!!!!
There were recently 2 litters in Hawaii but I think all have found homes. Ill keep an ear out for you. You should join the Hawaii chapter of the Boxer Club, they have a email group thats a good source of info locally. Good luck!