I'm not sure whether EMC's "SAN Copy" supports HP EVA's.
Anyway, depending on the EVA you have your options may be limited. What you could do, is to find out which (common) ESX versions are supported for your EVA and the VNX5300 (see http://www.vmware.com/go/hcl). Then use e.g. one of the hosts (with an appropriate ESX version) as the transfer host, which you connect to both storage systems to be able to migrate the VMs.
Other than this (although probabaly not the preferred way), you could use this as a test your backup application, and restore the VM's on the new environment from a current backup.