To install, simply click 'Install'; the configuration parameters should not need modification as the template within CA already defines the necessary parameters.
As a docker image can be created using various OS bases, the image choice is entirely the users choice. Recommendations of a specific image from a specific maintainer is beyond the scope of this guide. However, to provide some context given the number of questions posed regarding the various versions available:
The support for a given image is provided by that images maintainers, while support for the application itself remains with the developer - i.e. LinuxServer.io supports the docker image of Scrutiny which they create, to the extent an issue is specific to that image. If an issue/enhancement pertains directly to the source code, support would still come directly from this repository's contributors.