I’m a bit confused. It feels like you may have two questions.
Latest is sorted by post date. Perhaps you mean “instead of Suggested, have it be a truncated Latest”?
What topics display in the Suggested are based on several things - the general result being what a member is most likely to be interested in reading next.
It sounds like you may want something like a “put all the images that are in all of the posts in this topic into an image slider”. Or maybe you mean “go to another topic in this category that has an image in a post”.
The first would require a plugin, the second should be what happens as long as a member sets the category to Watch.