You might want to ask the folks at tirerack.com.
Personally, I would not degrade handling by switching to that aspect ratio.
I do know that 225/45/18s work very well.
I wouldn't recommend going from a 45 to 55 series tire. Much larger diameter. As concept said, a 225/45-18 will work just fine. A little wider and a little taller, but not by much.