Hard to tell from your pics, I always luked my bunks to be wider than narrow for better support on an aluminum hull. As far as keel rollers...you can't have to many. If you have enough abd spaced properly, they should never cause an issue/ damage to the keel. Been trailering aluminum boats for almost 60 years, no problems if trailer is set up right. Just keep in mind, you can't have to much support !!