Parallel to usb or you can get the network card installed. Network is preferable in my experience. A quality parallel to usb is probably worth the cash.
You can:
- run a rip like accurip as it's driver
- install Fusion or something similar and use the Epson drivers via a Windows XP vm
- get a standalone windows machine as the rip station and networks that computer to your iMac, drag and drop files
- print using Gutenprint, it does work and will generate nice films but you will need to get in there and test and tweak the settings.
Epson abandoned support for the 3k many moons ago so I think Leopard is the latest native drivers they released. May or may not work with the newest Lion or whatever it is...they're going to run out of cat names at some point.