Although scanning and outside printing are viable options at the technical level, it may be that the ultimate emphasis for publication purposes should be on controlling the images yourself. Thus, the 8x10 conversion Frank mentions might be a good option if you have a Beseler 4x5 enlarger. If not, another alternative would be a used 5x7 Zone VI enlarger, as they come up on eBay from time to time. They aren't much bigger than 4x5 enlargers, depending on which model you get. And, the typical price is about the same as buying the Beseler conversion new.
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