Hi lightpers. I like the Sibilla, too. For me, the Kipper is easier to work with than the Sibilla, because there are fewer cards and the nuances of the Sibilla seem to be built into the 36 Kipper cards (enriching their vocabulary, so to speak).
Since the Sibilla is your favorite oracle deck, I think you'll take easily to the Kipper. Likewise, I find my Lenormand studies have established a solid framework for understanding how the Kipper cards work - one only has to modify or reframe some familiar approaches.
It is fascinating to me, how all of these oracle systems function on similar tracks - it's understandable why some people even combine them, though I've never felt inclined to do so.