I would like to work on your project, Please share your requirements to send you specific detail about its solution. at the moment I am going to share with you, my last project in a bit detail.
I developed CRM for a company to manage franchise, labs and customers. It's a complex system and providing multi levels options for each group type. it's based on CodeIgniter.
I have attached a screenshot of it to give you an idea about the Web app I developed.