Linux integration with OSX (Open Directory + Samba 3 – as PDC)

I realize that I have the unlimited client license for OSX Server, but I would like to get more performance out of my OSX server by separating Home Directories and Group Directories i.e. file services to a distributed Linux server running Samba 3.x. The questions I have are focused on this: How does one integrate Linux Samba 3.x into Open Directory / Samba such that 1. Users can use their Open Directory accounts to access the Linux samba server without having to relogon or authenticate. 2. Can Linux Samba be configured to communicate to the OSX 10.4.8 Server to lookup account information against the OpenDirectory (OpenLDAP)? 3. Or Does the Linux Samba Server look at the OSX Server (Open Directory /PDC) server as a PDC under a given domain-- defined under OSX? My clients authenicating against the server are only XP Thanks! Vuong