IMHO, for any service provider to be taken seriously, they need to have a backend SAN supporting at least RAID 5, with automatic disk sparing enabled. The server should have two dual-port HBAs to support an Odd/Even redundant fabric design across two SAN switches.
If one decides to go the iSCSI route, the iSCSI network adapters should be separate from the outbid NICs, and should still be two dual-port across two network switches.