The Ferret incident in GoF shows that Barty hates cowardice. However you could argue that he was acting as he felt Moody would act at the time. There is still his hatred of the Death Eaters who avoided Azakaban and did not try to help Voldemort (that could be an argument for Hufflepuff though). He did deny the charges but he is still one of the few people who tried to find Voldemort after his downfall. So Gryffindor or Hufflepuff as his house, though i would not object to Slytherin.