IIS with .Net does not sysprep well.
The simplest clone is to simply copy the VHD and make a new VM using the copy.
Thre is no problem until both of them are on the same network - this is where rename comes into play.
Also, you can always boot the copy of the VM without it being attached to the network. While the VM is isolated you would move it ot a workgroup, rename it, then power it off, attach it to the network, and then join the domain.