When you install the SDK there is a folder with external templates -C:\Program Files (x86)\Telerik\Sitefinity SDK 4.0\Resources
. All templates can be exported with Reflector as well.
I suggest that you should use custom fields
instead of trying to modify the templates. Custom fields can be added from the UI and there is an option to create a custom controls that can be used as a fields in the view.
If you want to arrange some of the fields you should change the definition of the view which can be done from the configurations.
the Telerik team