I’ve never used either of these companies, but I know institutions that have and have seen the excellent results that they provide. I’ve also dealt with representatives from both companies and have been impressed with their knowledge and concern for the items that they deal with every day.
Northern Micrographics – http://www.normicro.com/DigitalImaging.aspx
Backstage Library Works – http://www.bslw.com/digitization/
I believe both could provide the custom service that you are seeking.