BrownAmerican
Gryffindor, the way that the fan-fic described Harry's character would only fit with the gryffindor house. He doesn't really seem like a studious ravenclaw or a cunning slytherin. A hufflepuff could be possible but it doesn't really fit enough. So in my opinion, he should be a gryffindor since there isn't really any difference from his personality from the canon and the fan-fic other than being a more active prankster.