Activate Windows 8 with Server 2008 R2 KMS Host

I have a KMS host running Server 2008 R2 sp1. I have licenses and a KMS host key for Windows 8. I would like to use my existing server to activate these licenses. I've successfully applied the update referred to at this link and restarted the server:

http://support.microsoft.com/kb/2757817

However, I cannot add my Windows 8 KMS host key to Server 2008 R2. I get the following error:

Error: 0xC004F050 The Software Licensing Service reported that the product key is invalid.

From what I understand, I need a Server 2012 key instead, because for some reason Server operating systems will only accept Server keys. We do not have any Server 2012 licenses, and so I don't have access to the right key (talk about brain dead). In other words, I own a bunch of licenses that I can't activate.

I know I could use the MAK key, but we have public computers labs. Re-imaging (and therefore re-activating) these public machines is a frequent occurrence. We have a similar policy for our classrooms. I'd burn through my MAK activations in just a couple months if I went that route.

Is there a way around this problem? Do I need to purchase a Server 2012 license that I have no immediate plans to use, just to activate Windows 8? If I do, will that reset my activation count?

If my Google-fu is correct, it unfortunately looks like you can't do this.

Paraphrasing the TechNet post:

You can't install the Windows 8 KMS host Product Key for Windows on Windows Server 2008 R2. You can only install the Windows 8 KMS host Product Key on a Windows client operating system (i.e., Windows 7 or Windows 8).

If your KMS host is a server operating system (Windows Server 2008 R2, Windows Server 2012) then you will have to apply the Windows Server 2012 KMS host Product Key. The Windows 8 KMS host Product Key is insufficient.

This is similar to way that Windows 7 / Windows Server 2008 R2 KMS Host Product Keys work. You need to install the "server products" KMS host Product Key when your KMS host is a server operating system or you need to install the "client products" KMS host Product Key when your KMS host is a client operating system.

I think your best bet is to designate a Windows 8 host as a KMS host and activate your machines against it.