Bert,
How do you print 500 MB of ll in one minute--I am sure you have said this multiple times but I haven't gotten it yet.
Gigabit network+good client machines (SSDs+i7-2600K SandyBridge Processors.) Gigabit can transfer files at speeds of up to 125 MB/s off the server and the processor (which is better than most peoples' severs) can combine them with no trouble. Then, burn them to a disc. Last part is probably the longest.