Vector Illustrations and Diagrams for Textbooks

I own the rights to a number of textbooks which include large numbers of images, graphs and diagrams. These have all been copy and pasted from the Internet, and I'm after a graphic designer to produce our own versions of them. All the diagrams should be consistent with one another and adopt similar colour schemes etc. We have had freelancers do this for us previously. So we expect illustrations in a similar style. I will provide three examples of previous work to freelancers we are interested in working with, and then ask you to produce your own version of a particular image. This will be a trial before we hire you. Most diagrams/illustrations are quite simple, but there will be a few which are a bit more complicated. I would expect every illustration in vector format (.AI) and will also ask for you to produce some .PNG files for each one in a specific size. If you do a good job at this we can provide a huge amount work of this kind in the future. Note: the final designer will be expected to sign a contract, which will include confidentiality agreement. This work cannot appear on any portfolio or website, and cannot be discussed with others. We will own all intellectual property rights to the final work. To start with, we'll want a designer to do 50 images. Please provide an accurate timeline. We're looking for someone to do this in less than a week. Thanks!