Hello Josh,
We previously had the iRC3220 (a slightly later model to the iRC3200) with the imagePASS-C2 (aka Fiery) and it worked fine as a network printer from 10.4 and 10.5.
You can download the driver for the imagePASS-C1 (which I believe connects to the iRC3200) via this
link. This file is compressed in zip format. Simply double-click to unpack and then run the OSX Installer located inside the Printer Driver folder. This will install the files to your Mac so that you can add the printer.
Now, to add this printer you will need to connect to it via Ethernet from the Mac. There is no way to bypass the imagePASS and there is no USB or Firewire on the imagePASS as you have seen. Assuming that the printer is already connected to your network, you should be able to add this printer using AppleTalk (if it is enabled in the imagePASS) or via IP.
To add the printer via AppleTalk, simply select to Add and then select the AppleTalk icon. If your Mac is using AppleTalk and the printer is using AppleTalk, then it should appear in this view (probably something like iRC3200-C1_print). If the imagePASS does not have AppleTalk enabled then it will work fine via IP (I would actually recommend using IP rather than AppleTalk).
To add the printer via IP, get one of the Windows users to print a test page as this will give you the IP address of the printer. Then on the Mac, select to Add and choose IP > HP Jetdirect-Socket for the protocol. Enter the IP address of the printer, change the name to something more meaningful and for the Print Using menu, select "Canon CLC-iR C3200-C1 PS Ver2.1". When you click Add you will be prompted to select which finisher and how many paper trays are installed. Select the correct options and click OK to complete the printer queue creation.
Now you are ready to test a print. While the look of the driver is not the same as your Windows colleagues, it will certainly provide you with all of the options they have.
Hope this helps. Reply if you need more assistance.
Pahu