I agree - both are good campgrounds, with very different experiences. I actually prefer Pancake Bay for the lake-side experience, and Rabbit Blanket in LSPP. In Rabbit Blanket, the first loop is for people with trailers/RVs, and the second loop is for tenters. (If you're towing, don't go onto the road to the second loop by accident like I did. Getting up the hill was ... interesting ... :) Did it though.)
Shopping: Wawa has a good grocery store and a Canada Tire. White River has a grocery store and hardware store. Marathon (NE corner of the lake, up past Pukaskwa) has a wider variety of stores and a small mall.