@vetroartefatto: Sorry but I still didn’t quite get you. You can use any content in Slider, i.e. Posts, Pages, Category or Custom Images. But Featured Content is not the slider, it has a column layout and is totally different from Featured Slider. I checked the above site you’ve mentioned, the Slider is quite similar to the Adventurous Theme.
Let me know further if I can help you further.
Regards,
Mahesh