Actually, the Xerox printers may very well work. Xerox is one of only a handful of dwindling companies that still make true PostScript printers, and not through software emulation and host-based printer drivers like HP. Yuck. You can probably print to the printer using the generic Adobe PostScript printer driver or LaserWriter driver.
I have a relatively new Xerox 6600DN (regular toner, not wax) I bought a couple years ago. I can print to it from any Mac in my house, even those running System 6. Excellent printers. I like them a lot. Full color with duplex and networking. Even
still supports AppleTalk and Netware.
My experience with HP in the last few years has me really mad at them. Their insistence on software emulation and host-based printer drivers is horrible. Every time there's an OS update (even a minor
point update), none of the HP printers work. We have to wait for Apple to release a 300+ MB HP printer driver update, which could take as long as a month or two.
Xerox, on the other hand, is all handled by the hardware. The software is good for all the extra doodads you can add to a printer, like secure prints, delayed prints, or even stapling and binding if you have a fancier one. But in the end, if all else fails, you can always print to it using a generic PostScript driver. Even so, they update their drivers in a day, sometimes in a few
hours, after a point release of OS X. I'm very impressed.