Operating on the assumption that you're planning on printing on a wide format machine, here's the direction you should head: uprinting.com, overnightprints.com, and any of a dozen other on-line OFFSET printers.
Whomever you chose, call them, introduce yourself to the staff, and get a trade discount. Try for %20 at which they will balk with such a low volume but they'll all automatically give you 10%. Take whatever price they calculate for the job, less shipping, double it and add back in the shipping. If that's unacceptable to your clients, walk away. Whatever you do, don't run the job as you've described it on a wide format ink jet printer. that's a guaranteed loser. That and you absolutely positively cannot compete, quality-wise, with offset printing for this kind of job. Or price, most likely. Don't do job printing with large format ink-jet tackle.
If you do end up going with an on-line outfit, send them 300ppi RGB jpg files. If they balk at this, some might, stand firm and demand that they deal with it. If necessary, jack up the quantities of each item to a number guaranteed to be produced via offset and not digitally.
If, on the other hand, you're using offset equipment and not large format gear, then never mind.
