Hi, I am a finishing neuroscience PhD student with both an MSc in physics and a medical degree. I have collaborated with a number of institutions in Europe and written several articles, including one in the Journal of Cerebral Blood Flow and Metabolism (Nature Publishing Group). I have managed and completed several research projects from ideas to publication in mathematics, biophysics, neuroscience, and epidemiology, working with mentors and students alike.
If you don't take it too personal, let me share my opinion, as I sense some frustration through the job description. The quality of the results you seek from the applicant really depends on several factors. To be honest it would be more informative to share the details of your research project, without it I cannot really tell what type of work is needed and in what scientific field. But some factors I list here.
There is the cycle: ideas, information collecting, planning, experiments, calculations, analysis, creative solutions of arising problems, reformulating hypotheses and designing new experiments, assessing combined results, interpreting, discussing, scrutinizing, publishing etc. I assume most of the above is relevant, starting from the analysis part, as you hint this job as an almost complete research project.
Also, the scientific field will determine largely the type of person you will choose, as expertise at the PhD level is probably needs to be in the same field, or at least strongly related. I wouldn't expect great results from anyone who has not worked at least a little bit in the same field.
So it is important to discuss the details, and only then we can agree on how we collaborate. If there is a real chance of success, including the scientific soundness of the project, I will maintain my bid. I highly encourage you to choose someone, who has guided whole research projects from start to finish, or even better, who successfully helped PhD students complete their projects. Otherwise it is likely a waste of money and time.