Green Belt Assessment Centers

Hi
Hope you can help. I need to internally recruite some people who will go into a role that is 50% Green Belt and 50% Day to Day. These people will have no previous Six Sigma experience and will be trained etc after they are hired.
I am planning to run assessment center for applicants to try and select people who have the right competencies for the job. Does anyone have any suggestions, procedures, documentation etc that may help in discovering if they indeed have the competencies required?Any help much appreciated.
Paul