Bren effectively closed this discussion, but here is what we got to work:

1.  Installed Windows 2003R2, and added Services for NFS and User Name Mapping

2.  Set up empty user and group password files, chose to use password and group files and pointed to those. Also edited c:\windows\msnfs\.maphosts to include the names of our esx servers.

3.  Set up a share giving Everyone read access on the Windows side and allowing anonymous access/all machines have read access on the nfs sharing tab

4,  On our NFS hosts went to configuration - storage and added a Network File System with the servername and /share name, checked the read-only box, and gave the device a common name.

5.  From the VI Client you edit a vm's settings so the cd/dvd points to  a Datastore ISO file and you browse to your share and choose the iso.  Be sure and check the Connected bos at the top.

This method allows all servers to attach through nfs regardless of whether they are attached to the lun hosting the iso's.  Also, connected devices do not interfere with lun numbering.