Go with the 225/40. It won't throw your speedo off by that much, it will be very close to stock, the 45 series will effect the speedometer and odometer readings. My wife has 18's with225/40/18 tire size. We lived in upstate NY so I know the bad road conditions. They were very tolerable with a decent all season tire and the HFP suspension. She has Falken 912 tires. They are quite comfortable. I was very surprised. If you do decide to lower the car a bit 1" should do a nice job of improving the wheel gap and not killing your ride comfort.
I drove around at almost a 2" drop and had no issues with snow or roads. I was snowplowing a bit when it got deep though. That paired with stiff struts and the ride was definitely harsh. If you are somewhere between our two cars I bet you wouldn't notice much difference.
