OK, I'm not trying to bash CWEs or CWIs, but you may want to find a SCWI to work with you if you are looking for a consultant to guide you through this process.
The CWE is not a CWI (he may be, but doesn't have to be). The CWE and CAWI require the same passing score when taking the CWI examinations. There is nothing in the "job description" that states a CWE is qualified to document a PQR or develop a WPS. Likewise, there is nothing in the listing of table 5.1 (of B5.1) "job responsibilities" for the CWI that includes developing a WPS, although he can witness the PQR.
That isn't to say there aren't any CWIs with the experience to do what you are asking for, it just that it isn't expected that any (or all) CWEs or CWIs are capable of doing what you need to have done.
Best regards - Al