I'm now giving thought to running wider tires in the FRONT?
Front 225/40r18
Rear 205/45r18
Surely that makes more sense on a FWD car?
That does make more sense, although usually only if you are planning to put on slicks and drag race with the car. I've seen a few Hondas around my area with wider tires up front, and it just looks weird to have a deeper dish in the front than the back.
It'd just be easier to get a matched set to maximize your grip on all 4 corners, plus then you can rotate your tires to ensure they wear evenly.
NOW, here's a fun idea for you. There is a set of wheels out there that have both a regular AND concave configuration, but the exact same stats in every other area, which could make it appear you have a staggered set of rims, even if you don't.
They're called Alutec Poison. They come in Polar Silver and Matt Black. They have an 18"x8" set that should fit. In theory. PCD and Centerbore is correct, and there are others who have fit 9.5" wide rims on with spacer. So in theory 8" should be fine.
EDIT: I actually like this idea so much, I'm scrapping my plans for the Sparco Pro Corsas and will probably get a 'staggered' set of Alutec Poison in Matt Black.