I quess you already has a RIS deployment running serving deploying your windows clients.
The "issue" with RIS in the microsoft world is legacy, you might thinking on changing to WinPe, deployment workbench ect. which also gives you the changes to deploy both 32 / 64 windows.
What I am doing ( also living in a mix M$/*inx world, because of my wife and work) is using linux PXEboot to boot up Winpe from a linux box, and deploying windows (server/Xp/vista/7) from WinPe.
The WinPE deployment automatisation is created by "MS deployment workbench".
I have been writing a small howto on this in danish on what needed to be changed on the pxe server, ( http://www.net-help.dk/index.php/deb...e-med-tftp-hpa
( the hardest work is making the "WinPE" boot files able to pxe boot using bcdedit, but there are a few howtoo's on this on the web )
I have not had the time to test if it's possible to use at samba share as the deployment share for the above configuration.
I quess that this is an total change off your current deployment way, and not is what your 100% is asking for, but it works and might be the solution on the loong term.