Campaign Operations is the book you're thinking of. The Starterbook: Sword and Dragon campaign framework is an early version of the Chaos Campaign rules. Campaign Operations is the most recent form of those rules, but with all the (optional) bells and whistles. Sword and Dragon is good from the standpoint that it's all laid out for you as the GM - you don't have to worry about making your own missions or setting up things like lists of gear available for purchase. Campaign Operations is more of a toolbox to build from scratch what Sword and Dragon already is.
The one thing that annoys me about Sword and Dragon is the prototype gear - it introduces players to the early forms of the recovered Helm Core equipment, but from a rules standpoint, that equipment is more complicated than the final versions because a lot of the pieces have extra rules to make them a worse version. My advice would be to either skip the prototype gear entirely or just use the final versions.