Image enhancement, bulk, making print ready

HI

I need to outsource my image enhancing for various magazine features.

As a rule of thumb, each car feature has approx 16 images, some large and will require background work and some small that will purely need lightening/ colour balance etc.

I might say, please make lead image with a B&W background but colour enhance the drainpipes in the background to red or the yellow lines in the road to yellow - whilst leaving the car.

I am looking to outsource approx 10 features every 2 months (not spaced out over 2 months but the 10 feature's images over approx 7 day period - so approx 120-160 images).

Images will usually be supplied as jpg, sometimes tiff / png etc. We will always require them back in CMYK TIFF.

Images would be transferred via our ftp site and communication via msn preferred.

First lot of images ready to go. I am happy to send a sample from a feature if you bid.

This is not a high paying project. You may price per image or per feature, whichever you prefer.

As with most print media time is usually of the essence.

Any q's please ask.

ADDITION

I need to be a bit clearer about the number of images and workload involved - this is approx 1-2 days work for all images - 80% of the images are simply lightening and basic retouching in preparation for print. - 10% are proper enhancements as per the brief - for covers and lead images etc - the remaining 10% is somewhere in the middle.
Thanks
Lesley