Can’t choose startup disk after wiping hard drive from OSX Utilities
Well, your having wiped and reformatted the HD, there IS no bootable volume on that machine, so that HD cannot be selected as a bootable startup disk, as it has NO data on it at all, let alone a full Mac OS with which to boot.

You'll need to see about getting that OS installer downloaded set up as an ISO on optical media using a different machine to do this, and then running the installer on the target machine from the optical media I think, given the issues you're seeing when trying the network install option.