The Xerox 6604/6605 is no longer sold as new.
You might like to consider the replacement product.Xerox 6705
FreeFlow Accxes Submit reduces the time spent printing sets of PDF, HPGL, TIFF or JPEG files on a large format printer
Printer management software. Ultimate print management flexibility, FreeFlow Accxes Control workflow allows any number of print queues to be serviced by any number of printers using user defined policies.