A474a/b: Yes, but it's unclear which body type they fall under. It would probably be either Saurian or Quadruped based on the picture in B3, with the DM making the final determination since they are not on the table specifically. As for resizing - wondrous items resize to fit the wearer, and so does magical jewelry (so that will cover you for most body slot items and rings.) Weapons and Armor don't, but that shouldn't matter for a familiar.