Advanced Audit Policy Mixed OS

Hi, 

Just for a bit of clarification if possible, I am configuring the AAP for a domain that has 300 domain controllers that are a mix of W2K3, W2K8 and W2K8r2. From reading these settings are only for W2K8r2 and Win 7, although the Windows 7 is not relevent as this will be linked to the Domain Controllers OU. Also, that the origional Audit settings should not be combined with the advanced settings.

So, my thinking is:

Create a new Policy and filter for only w2k8 copy the settings that are from the Default Domain controllers policy that is currently applied to all DCs and set the policy to enforced?

Or...

Copy the original Default Domain Controllers Policy filter for just w2k8 and then filter the origional for all other os's

Any other ideas?