If you're using a UNIX server,
and if that server can access the client's printer via an Internet Printing Protocol (possible in an intranet configuration), you can use
CUPS (using it's Ghostscript interface) to directly send PDF files to your client's printer.
That is how our ERP system prints graphical documents to our printer:
The printers have a fixed ip address, and are reachable from our unix server.
On the unix server, all our printers have their own print queue.
The reporting system generates pdf files, and sends the file to the appropriate print queue on the unix server.
Regards, Jan