But flares would not look good unless you went with 20"s that are wider so they match the flares width.
Wide tires look good with or without the flares, but narrow tires probably won't look as good just with the flares. Have you ever seen one with 19"s? Unless your 19"s are wider than the stock 19"s (9"). Imagine, the sports edition's rears are 11" wide, that's 2" of add'l width.