I've been searching high and low, but apparently they're exclusive to SCA Performance, and I haven't found anything on their site where they'll sell just the wheels (or any other bits of the BW packages, apparently). The crazy thing is the factory 22" Limited wheels are VERY close to the same pattern, minus the dish. If one were to mask off the beveled edges of the 6 largest voids, paint the whole rim black, then peel the masks, they would look pretty dang close. I don't know that I'll go that far, but with the Plasti-Dip stuff these days, it could be fun to try after the Goodyears wear out and it's time for some new skins.
Here's the pic I saw from the Craigslist Ad, and just had to have it.
After 4 years of rust replacement, fabrication, rebuilding, cuttin', beatin', bangin', grindin', sandin', and more money than if I would've bought a newish GT-500, here we are:
Here's a link to the web page I made for historical purposes (the blog's not quite complete yet, but there's also a link to the FB photo album with almost 400 pics of all the gory details):
http://www.mister4x4.net/cars/Mach_1.htm