NFS Datastore hosted on VM?

I had this ~~brilliant~~ idea to move our ISOs datastore to an NFS datatstore to make it easier to delegate permissions for uploading content. There would absolutely only ever be ISOs or VM templates residing there, never any live VMs. My question is, how do I do this without creating a situation where the hosts either won't boot, or wait for an excessively long timeout on boot if the VM is not available? I'm thinking of a situation where I need to hard powerdown everything for some reason.