vista purchasing

Is there somewhere I can purchase keys for my product? I've got the Microsoft Windows Vista RTM Build 6000.16386 AIO DVD ( Via my usenet client ) and I want to purchase keys for whatever versions I will be installing on the PC's I build.

Mainly I'm looking for OEM Ultimate x64 keys that will work with this for ex..

I'm building about 6 or 7 systems within the week and I am allready signed up with partners.microsoft.com but I don't see where I can just buy