Sourcing researchers, post-docs and assistant professors

We would like an experienced talent sourcer to source candidates for an upcoming programme. We have a defined criteria list and lots of past experience of what works and doesn't work so it will be relatively easy to find the people.
We're looking for high quality candidates. We're looking for a list of 450 candidates.
1) Data should be recorded according our pre-defined structure
2) We'll do a test of 100 candidates first to test quality. If we are happy with the work, we will commission for the next 350.