I've read Article ID:1522 which I post below. I need a little more info though. I'm getting an error when I try to install a 64 Bit driver on the 32 but 2003 OS, as I would expect. How do you get past the error stating that the driver was not designed for a 32 bit system?
Installing 64 bit print drivers on a 32 bitserver
Pharos Client Installation Packages created on a 32-bit server OS can be created to include both 32 and 64 bit drivers. In order to do this you will first need to install the64-bit driver onto the 32-bit operating system.
Once the drivers are installed Pharos can make use of both 32 and 64-bit drivers when creating client installation packages.
Provided your server runs at least Windows 2003 Server with Service Pack 2, installing64-bit printers is a simple process.
Run the "Add Printer" wizard, and install a printer with the 64-bit driver. Once installed you can delete this printer object, the driver will remain on the server.
Next, select the Spool/Held Queue object that you want to have 32/64-bit support, right click on the object and select properties. Once properties is open, select the "Sharing" tab and the "Additional Drivers" button. If the 64-bit driver installed is the correct version you'll be able to add it to the list (check it).
Repeat the process with the Printer Queue object.
Build or re-build the Pharos Installation Package normally and both 32/64-bit options will be available.