Did a quick test fit with a 3mm spacer.
Kinda hard to capture the amount of room there is on a picture, but it's really not a lot.. maybe a mil.
Think I might just bite the bullet and get the 255s (Michelin Pilot Super Sports) and look for a way to fit them once I have them mounted on the rim.
The issue with camber plates is that I'm not sure which ones will work with Tein Super Streets. If I can't go this route and the 3 mil spacer doesn't end up giving me enough room, I guess I can always go 5 mil.