Oh man, if they only made the CS2's in 19! I'd be tempted to go up to 20's for those, but I've already got the tiresHave you looked at Apex Racing? They've got some nice choices and can give you EXACT references for fit. They are doing 18x11 square. They have one of the very few 18 inch wheels that will clear big brakes. Takes a good deal of negative camber, front spacers, and relocating bump stop in rear. I prefer staggered for street driving, and extreme stagger for drag setup. If I ever get into autocross I'll get a square setup.
Here's a wheel that's not bad. When I ordered these they were out of the rear wheels. I ended up stuck with these:
https://www.s197forum.com/threads/20x9-shelby-cs2-wheels-for-sale.137566/
I looked at Apex, but most of what I was seeing were 6, 7 spoke wheels and I'm lookin for 5 spokes (solid or split)