On your forgestar look alikes, if forgestar themselves make the correct front size, perhaps you could sync up with someone here to buy 4 "fronts" and then split both sets?
Alternatively, there seems to be some "knock offs" in the wheel industry so maybe you could find a knock-off in the size you need that is close enough to the originals that you could do the same thing?
WARNING: Moderate thread hi-jack to follow......
I've never really been a "wheel guy", but after seeing the Volk TE37's I think I've fallen in love:
Those dished rears are just SO DAMNED SEXY!
I know it's different than what you were looking for, and is a complete hi-jack, but they have me curious about how they would look on an 818. I came across these when I was considering buying an FR-S, and reading up on mods for the car.