I've had a few large-format printers that I used with my Mac, all HP's, and they all had USB ports.
Best print server I've used has been an Apple Airport Express.
http://www.apple.com/airportexpress
Stupidly small, and does a great job. I have about 4 of the things, and even take one with me when I'm on the road so I can always have wireless internet in hotel rooms.
I bought mine for $89 each at the local Mac store.