Wheel size: Comfort versus handling versus power loss...

Questions about a 96 Corolla DX wheel upgrade...

I know going plus-size on the wheels and ensmallening the tires preserves overall size, increases handling, and decreases comfort levels inside the car due to the smaller, stiffer sidewalls. I also know that bigger wheels generally translate into greater unsprung weight, and this is obviously a bad thing.

My question is at what point the ride comfort begins to become degraded further than would be considered generally acceptable for a daily driver?

Looking on TireRack shows me a wide variety of 14" wheels...well, those are stock diameter and I already have an aftermarket set of those on the car. (Kosei Racing...a nice style, looking much like my old Superiors.) 15" is probably still too close to stock to be worth the upgrade. 16"...now we're talking, but I can't find a style that I like.

However, there's a 17" wheel that weighs less than the 16"s, has the perfect style, and is in a great price range.

Given that the eventual suspension setup of the Corolla is going to wind up being a set of KSport coilovers (either Kontrol Pro or GT Pro--7k/5k rates, I believe, non-progressive, although I do have a set of Eibach Pro-Kit springs) and the available engine power is going to be roughly doubled from stock, and that I do still want to preserve comfort for long road trips, is 17" just too big?

Thanks in advance.