St. Louis Rams

I own a black and gray stripped '96 Mustang GT. I've always loved white lettered tires, and I want to put them on my car, but I've been to a few shops locally to find size 225/60/16 white letter tires in any brand. I've been told no major company makes them. I was thinking about BF Goodrich Radial T/A with raised white letters, but I was told they don't come in my size.
My budget is, around $400 - $600 with installation.

Are they a diamond breed? Can I custom order them? Is there an odd brand I can buy them from?

Shredding

I'm a fan of white letter tires too, and also had the same problem. I've been getting these white letter kits that you can add to any tires lately from www.ironcrossinnovations.com I tried some other things like tire paint, and searched online for white letter tires, but these tire kits have been working perfect for me. Hope this helps!