Little more searching undercovered the following
1.Create a new Virtual Floppy Disk in the Hyper-V manager.
2.Mount the VFD to a Windows (desktop or server) OS VM.
3.Mount the SBS 2008 DVD ISO in the same VM.
4.Start the SBS Answer File Generator Tool.
5.Configure the Answer File with the appropriate settings.
6.Save the Answer File to the VFD.
7.Dismount both SBS and VFD from the VM.
8.Create your new SBS VM and its VHDs.
9.Mount both SBS DVD and VFD.
10.Run the Win2K8 primary setup steps and the answer file will take over.
I will try.