CRM with CMSMS?

[CMSmonkey]

Has anyone successfully implemented a CRM (client relationship management) system with CMSMS?

I'm looking for something that can maintain client data from one module interface - something that can pull in their profile information (name, company, address, email, etc.), view their orders from the Order module, and maybe maintain correspondence (inquiries, communication, etc.). It would also be nice that you could enter a client's information in case they didn't use the Orders module (i.e. phone sale). If they decide to register through the site later, the profile could be linked somehow so there wouldn't be duplicate entries from the same person (one entered from the admin side and one entered through self-registration).

Any suggestions are appreciated. Thanks.