Try these folks They have advertised in Road&Track for many years .In years past I bought Boge and Konis at prices that were lower than just about anywhere else
They are RD Enterprises 1-800-683-2890
On the web they are WWW.shox.com
Let us know if they beat the others on the price
I have suspected that the Magnas offered by Mustangs Plus are OEM'ed KYBs. I'm not sure about that though. They are cheaper but have the same guarantee. If they work as well that might be an idea. I bought my KYBs in '92 from Canadian Mustang for $99.99 (Canadian) and they are still working well.