Colour correction of around 200 images from various sources

We publish an annual guide to ski resorts illustrated by around 200 colour photos sourced mainly from tourist office libraries. These images need to be straightened, corrected to achieve sensible density and contrast, and neutral colour balance, and sharpened. And converted to CMYK of course. We normally do this in-house but are short of resources this year. The work needs to be done in the first few days of July. We envisage payment by the hour. The attention each image needs varies hugely, but we expect the job to take about two days in total.