Have you looked?

Pilot super sports are available in 225/40/18....
http://www.tirerack.com/tires/tires...ear=2015&autoModel=Civic Coupe&autoModClar=SI
If you're unwilling to run an all season or a dedicated winter setup for snow then this is really the only option I would suggest.
The Falkens should not even be on your list. There are other Falken tires available but the rt615 is not one I would suggest you even try to run in the rain. Its in the same category as the Toyo R888. Those are street legal motorsports and DOT approved track competition tires. Not for DD-ing your Civic around. Those should really be reserved as track day and auto-x tires. Even at that, most guys won't run that extreme of a tire unless they are top tier drivers.
I've been running a set of RE-11As from Bridgestone and they are supposedly the "best" in wet conditions of all the extreme performance tires. Let me tell you, they are scary in heavy rain and even light rain means extra caution. If thats a "good" rain tire, I would hate to see what happens with one thats worse. The last few days have been cold and I've been lazy about getting the snow tires on. These tires are getting very very skittish on cold pavement. It seriously feels like the alignment is way off from the way they pull when its below 50. Not below 40, 30, freezing, snow, but 50. Its noticeable.
You also don't have to use two sets of wheels. You can always have the tires swapped. Thats what lots of people do. Whatever route you choose, be careful.