Wheels for winter tyres????

[gsewell]

Hi,

I've got a 2nd Gen Cayman and have been looking for wheels for my winter tyres. The official fitment is:
front: 7*17" ET55; rear: 8.5*17" ET40
So far none have come up on eBay or Pistonheads. However, I notice quite a few wheels for older Boxster/Cayman cars that are: 0.5" narrower even though the tyre fitment for the car is the same (front 6.5"*17 ET55; rear: 8*17" ET40)

Is this likely to cause problems with handling (the centre line of the tyre is in the same place due to the offset being the same) or the OPC warranty?

[UVB]

There's a set of 17" wheels with PS2's on Ebay that say they came off a 987 therefore should fit (assuming they were original). Spec states they are 6.5x17 front and 8x17 rear. Offsets stated as 55 & 50 but doesn't say which is which.

Item no. 220927599552.

If you find a set of 18" Cayman wheels for a good price anywhere PM me - I'm looking for a set at the moment for winter tyres too.