The EqualLogic you have listed uses 10GBe ports.
What config are you going to run the Storwize in?
1 Gbps iSCSI - Standard or optional 8 Gb Fibre Channel or 10 Gbps iSCSI/Fibre Channel over Ethernet host ports?
Also, Dell isn't listing the PS4110X on their site anymore... Are you going with 7.2 or 15K drives?