Well, for the Linux boxes, NFS, but try to use latest ie NFS v4 which uses TCP and is much more reliable.
For MS boxes, your choice ... Traditionally Samba / CIFS, but it can be fiddly, or you can add SFU (Services for Unix) which should give you nfs client sw.
More consistent for management purposes, in fact you could probably automate some of the setup; just have a list of wkstns and get the server to automatically create/export nfs shares.
If you go Samba, I'd avoid having CIFS+NFS shares on the same disks/mnts....
The RHEL manual here explains (HOWTO) NFS + CIFS pretty well http://www.linuxtopia.org/online_boo...ion/index.html