Universal Containers (UC) works with a dealer network to sell their products. There are approximately 5,000 dealers that do business with UC and UC has purchased a Partner Community to interact with each of their dealers on Opportunities. Each dealer is structured so that there are a group of managers who will oversee a larger group of agents. UC would like to set the Organization-Wide Defaults to Private for the Opportunity object, both internally and externally. Within each dealer, there are a few agents called Lead Agents who should be able to see the Opportunities for all of the other Agents at the dealer. What is the optimal solution for an Architect to recommend?