I'm sure I've read that there are people who use Kings for the low grit bevel setting stage.

Aside from that, my personal preference is to avoid adding too many stones too quickly, especially when talking about finishers. My advice would be to get to know the Norton well before acquiring more stones. You can get a very nice shave off it with practice and care, and the skills and technique you develop while pursuing that goal will hold you in good stead into the future.

Search out a thread called "JaNorton". There's some very valuable information in there regarding how to get the most from the Norton 4/8.

Good luck.

James.