Migrating 2003 Clusters for 2008 R2 (DFS and SAN considerations)

Hi,

 I have several 2003 fail over file clusters, as well as 2003 R2 clusters which I want to move to 2008 R2 fail over clusters for file services.

I have around 5TBs of data, the 2003 file data is all sitting on a couple of different SANs, I'm not using DFS replication, however some of the data on the cluster is a DFS target. I'm after a quick and easy(ish) method of migrating the data so that I don't have recreate file permissions or copy SAN data.

So far, I've considered using the file migration toolkit and the cluster migration wizard, but am not sure on the best path.

Please advise.

Thanks

IT Support/Everything