Help Needed for Best Swiss Pass or Card to Purchas

Hi tbsnc! I'd say the Regional-Pass Bernese Oberland is a great choice for your plans, since you intend to focus on the Lauterbrunnen area. If you'll be traveling in September or October, you may even profit from the current 2 for 1 offer. Part of the route from and to Zurich Airport is covered by the Regional-Pass too. Just click the link 'Overview of the network on which the Regional-Pass Bernese Oberland is valid' at the Regional-Pass page for specifics.
Does this help you decide? Regards,

Hi Ted! The Swiss timetable allows you to find out about traveling costs. This FAQ explains how to do so. I hope this is what you're looking for.

In your case, the exact price depends on the route you pick from Zurich Airport to Lauterbrunnen and on whether you intend to use a free travel day for your inbound trip or not. If I were you, I'd travel via Lucerne and Meiringen, as this is a great scenic route. It takes a bit longer than the most direct route via Bern, but in my opinion it's worth the extra time. Just enter 'Meiringen' as your via-station in the timetable for an overview of these train connections. As the map I referred to shows, your Regional-Pass will be valid from Lucerne with a 50% discount. From Brünig-Hasliberg, either a 50% discount up to Lauterbrunnen applies, or free traveling if you use a free travel day.