All the placements are great, but if you want you can instead move the 468x60 ad underneath the post and above the comments. That converts pretty well for me it actually doubled my ctr. You can also use image ads with text ads on all of them, that will get you higher paying ads also it tends to make your traffic more aware of them.
My preference if at all possible is always to try and find a way to get your ads as near the left hand side as possible as that is the side that the eye is automatically drawn to to ge to the menu options hence the CTR will be higher.