A computer retailer isn't really the way to go for industrial-strength machines. Hopefully Gamerprinter will be along shortly to help out with this one, as he runs a print shop and probably knows more about the topic than any of us.

For digitizing, you'll want a flatbed scanner for work up to 11 x 14" and a traction-fed scanner for large-format pieces. You'll want to weigh the costs of items like these against how much a mapmaking company is going to be bringing in, though. It may be more economical to plan on subcontracting printing and large-format scanning to another company, particularly if you're looking at mass-market maps, for which you'll want hundreds, if not thousands, of prints.