Cap Feeder Starwheel Integration specification should start with the real closure.
Starwheel capping lines need cap feed timing to match the index cycle. The feeder, chute, escapement and sensors must be positioned so each bottle receives a cap without delay or collision.
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.