An excellent reference document, and recently updated to include the new EVA arrays is the HP StorageWorks 4000/6000/8000 Enterprise Virtual Array and 4100/6100/8100 Enterprise Virtual Array configuration best practices white paper (pdf – April 2009)
You can find this White paper, along with multiple other Storage Array Systems White papers at the following URL: http://www.compaq.com/storage/arraywhitepapers.html