I know for sure Mustangs Plus has them, but I feel quite certain that Mustang Depot and many of the other vendors have them. Jay, the owner of Mustang Depot, is a regular on this forum. Give his company a call or go to mustangdepot.com. I wish you luck in keeping one of those damn things on the front of your car, however. I had one on my '65 at one time, and within a couple of months, it was busted all to ****nit.
One thing I've considered on this topic is a fairly heavy gauge metal, aluminum, or stainless steel spoiler in the approximate shape of an aftermarket chin spoiler but with greater ground clearance, which would mount to the radiator support and/or front frame rails for rigidity (maybe 2 or 3 inches higher in terms of ground clearance). Attach NASCAR style rubber to the lower edge of the spoiler to extend it groundward with stainless steel rivets or allen head bolts. If you used stainless or aluminum, you could opt to paint it or leave it natural with a clear coat on it. I once saw a '65 coupe that someone had replaced the taillight panel on with stainless or aluminum. It looked pretty damn cool, and it would look especially cool IMO, if you had a matching front chin spoiler to tie it all together. What do you guys think?