Can the z3100 work that hard? In my experience, yes, at least if the machine is relatively new (i.e. too young to have belt decay issues). For that many prints, I'd have either a spare set of print heads on hand, or a supplier who can provide them overnight. And I'd be prepared to clean accumulated gunky ink from the underside of the carriage a couple of times during this long print run. When I've run a large set of prints (250), I found that I would get black ink dropping or smearing off the bottom of the carriage, so I had to interrupt the run and clean underneath by pulling all the print heads and using either coffee filter paper with distilled water to clean the heads and to work under the carriage (a tedious but effective method), or, if you save the little cleaning pads that come with the print heads, you can wet them with the distilled water and bend the stem to fit under the carriage. The machine itself seemed perfectly happy to print, and print, and print. I've been mightily impressed with the robustness of my 3100 over the years. (though I just bought a Canon 8300 from Shades of Paper---at this juncture in printer development, I think Canon has the best combination of output quality, build quality, price, and convenience of use.)
Congratulations and good luck with your big job!
David V. Ward, Ph. D.
www.dvward.comDavid V. Ward Fine Art Photography