Best of luck with your project.
However, I assume that you have thoroughly read Yolanda’s first post, and that you are happy with taking on the role of “self developer” ?
Presumably this implies that you are also aware of all of the responsibilities and risks that are associated with this role ?
How certain are you that the Project Manager and the builder are not associated in any way, other than from the fact that they have worked together previously ?
You mention that you have seen other properties the PM and builder have completed. Have you had the opportunity to meet the owners of these properties, and discuss the process, and to enquire as to the legal status of their property ?