Skill Requirements, Articles, and Products Required is the appropriate Field Service design. Work Types are reusable job templates. They directly associate the skills required to perform the work, the Knowledge articles that guide technicians, and the products expected for execution.
The Field Service data model separates the service requirement from its individual tasks and visits. A Work Order represents the overall job, Work Order Line Items represent component-level or task-level work, and Service Appointments represent the scheduled field visits used to execute that work. Choosing the correct level preserves accurate history, pricing, inventory, and scheduling.
The alternatives address different parts of the Field Service model. Service Resources are selected later by scheduling, and Service Appointments may be generated from work using a Work Type but are not one of the three supporting objects identified by the question.
This approach keeps the implementation aligned with the standard Field Service data model and avoids unnecessary customization. Study Guide reference: Managing Work Orders — Work Types; Skill Requirements; Knowledge Articles; Products Required.