Arms Unlimited is good to go. I've purchased a number of firearms from them over the years. For some reason, they have a special connection with Colt that allows them to get items that are not available elsewhere. For example, I purchased a Colt factory 9mm AR15 receiver set in tiger stripe camo. Colt never actually made complete 9mm AR15's in this camo pattern, but Arms Unlimited was able to get the receiver sets after they scrapped the project. Currently, I have a Colt M5 factory SBR on order from them. It just shipped to my dealer yesterday. They are the only company that I could find selling the factory SBR M5. I have not been able to find this package available elsewhere, so perhaps they have a special connection with CZ as well.