Work related techy sort of question....

Someone recommend me a printer! I have concluded that the source of my printer woe is not the server itself, as previously suspected, but the fact that the printer is nearly dead. Given it was a very cheap laser printer, intended for light home use, and we've been using it heavily all day every day for the past 3 years it's not done badly but I think it's time for an upgrade...

So, I need a black and white laser network printer, capable of duplex printing, that's hardy enough to put up with printing over a hundred sheets a day. And either has it's own server built in or will talk nicely to my Ubuntu server. Suggestions?