This was a HP EVA San solution with fibrechannel interfaces and hence somewhat costy, but it was used for the entire organization (file-clusters, VMWare-cluster

This was a HP EVA San solution with fibrechannel interfaces and hence somewhat costy, but it was used for the entire organization (file-clusters, VMWare-clusters, Exchange-clusters etc etc), not just the SQL Clusters. Apart from that teenie weenie bit about having an officially supported clustering-setup, I see no reason why you couldn't have used some random Linux iScsi NAS-solution, for instance powered by OpenFiler, which is 100% free.