Padus DiscJuggler can burn on multiple recordable optical drives at the same time. All you need is a Server case with extra IDE add-on cards (unless you plan to go for SCSI) and you can set up your own PC replicator system.
You will need to purchase a 2+ license on Padus DiscJuggler though.
Some other software can do this too, but DJ is the best IMO.
Hope that helped some.