Most people on here stick with the OEM Rays or go for wider or larger diameter wheels than standard, so narrow aftermarket ones are rarely seen or discussed. I would suggest you contact some of the forum traders as they may be able to get some in for you or alternatively try eBay as they often have narrow wheels for a variety of cars, like these for instance:
18" Infiniti G35 Mk1 Sedan 02 to 06 ZCW Shift Alloy Wheels Only 8B7C1E
Fitted with 15-35mm spacers they would most likely fit over your Brembos but it would be worth asking the seller.