It is currently not possible to use reference sets inside TemplateGrid templates due to differences in the rendering engines used by FormView and the TemplateGrid.
I'd suggest entering a feature request in MXDN.
This overview is already defined in the default System module. The System module is the module that all projects get by default on creating a new project.
The name of the form is: User_Overview
Please take a look at the form to create your own. It is important not to change anything in the System module, while this can result in failure of your project.