edacsradios.com/ is what I discovered from a seller on ebay, only one offering 1k radios programmed. Not seeing anything about non-transmitting radios and I don't think you could buy a radio and say program it for OKC without some sort of permission from OKCPD.
I saw that after I looked at the link you posted. Pretty cool. I don't want to listen to OKCFD that badly, but there are surely some who do. Pretty cool!
I like that they walk you through all the steps they take to render the radios safe for civilian use. I assume it's hard to get either the software the cable or both.
A kilobuck is a lot, but at least you get a professional grade radio.