Hi Paul,
I went through the same problem. I contacted local Jag dealer in Kent the part number is XR8 53595 and it is an 18 inch rim and red in colour. Unfortunately they are not stocked by Jaguar anymore and the only place to find one with the insert tool kit is Ebay and slightly used.
Hope this helps.
Mine is a 2014 XKR convertible so if I do have a puncher it will be cosy in the back seat when running on the spare, lol.
Cheers
Andrew