Basic RoboHelp should allow you to accomplish your goal. RoboHelp Server simply offers additional functionality that some folks find useful.
According to the Adobe site:
Adobe RoboHelp Server 9 software extends the managing and tracking capabilities of Adobe RoboHelp 10 software.* Automatically build multiple sections of a project, and then publish as a unified online information system. (This is possible to achieve with basic RoboHelp and project structuring)
Manage user rights and security, (This is possible to achieve using your Web Management tools - RoboHelp simply offers an ability to manage it within the Server specific bits)
and take advantage of simplified deployment and content configuration. Track and analyze data navigation patterns (also able to be achieved without Server using tools like Google Analytics)
and repeated search requests to optimize help content and enable powerful searches based on a wide range of variables. (RoboHelp Server uniquely offers this)
Rick, thank you very much for the quick and concise response.