@Crystal_MX-5RF recently fitted some to OZ Ultraleggeras to their 30th Anniversary RF:
I think they look rather tidy:
I would stick to 17" if you want a decent amount of rubber, depending on your offset you might be able to go wider than the stock 7Jx17 ET45. I have 25mm spacers all round but have slight rubbing , others have 20mm or 15mm without issues.