I bought a set of genuine 18" Jaguar alloys to upgrade my XK8 from the Wheel Collision Center in Bath, PA (http://www.wheelcollision.com/ Phone: (610) 837-8792 Toll Free: (800) 292-RIMS). They also do repair and re-chroming work by mail order. It was a few years ago now, but I was very happy with the service.
Glynn & Diane Kerr
'98 XK8 Convertible/'67 XKE 2+2 Coupe Srs.1/'51 Mk.V Drophead Coupe