The guy I would seriously consider is Jeff Tedford.
He is known as a developer of QBs- Aaron Rogers, Trent Dilfer, Joey Harrington, David Carr. Has 10 years of college HC experience, an additional 10 years coaching QB and OC.
An out of the box candidate, maybe worth a look
Not trying to be a smart-ass but Dilfer, Harrington and Carr do not represent an overall excellent body of work.