My vote for the pairing proposed is Harry/Padma.
Thought I prefer personnally a Harry/harem with Harry and three girls from the other houses (Padma or Luna, Susan Bones, and a slytherin girl like Daphne Greengrass)and perhaps a veela.
But it is your story.
Good Story. Keep the effort going.I like the idea of Sirus animagus form being a wolf.