btw, your zoning and registration will need to be done "blind". Host is not running operating system so it will not login to the switch nor will you be able to install any software until after OS is installed. Always perform OS installation with only 1 path zoned. After installation is complete, install PowerPath and add additional zones/paths.
I believe that you can use the Server Utility to register the host on the array and not need to manually the WWN's on the array. You can also use Host Agent (I would recommend this way) to automatically register the host to the array. With Host Agent you also will get bi-directional communications between the host and the array - this will push up to the array the disk labels (drive name D:\ for example).
The steps you've listed above should work. Just be careful that the first LUN you add to a Storage Group is listed as Host LUN 0 (zero) or HLU 0. That first LUN will override the LUNZ that you see when the host is connected to the array and not yet assigned a storage group and LUN.