Bulk Cap Hoppers specification should start with the real closure.
A bulk cap hopper is useful when manual cap loading is interrupting production. The design should consider cap nesting, dust, material finish, hopper access and the demand pattern of the downstream feeder.
For a better buying decision, the useful comparison is not only hopper size or headline speed. It is how the feeder behaves with your closure, how the capper receives the cap and how easy the line is to run after changeover.
The safest specification route is to start with real closures, target output, line photos and the exact point where the cap must be presented. That avoids choosing a feeder on a generic speed figure that does not match the cap or capper.