Jul 31, 2014 - 3:06 PM
Hi swisstrip25, and welcome to MySwissAlps!
Which pass is best depends on your final travel plans. It should actually be decided based on calculations as explained here. Without such calculations you'll have to choose based on general pros and cons.
In all, a 4 day Regional-Pass Bernese Oberland seems to be the best option for you. This allows nearly unlimited traveling in the Interlaken region. You'll only have to pay additionally for the most expensive mountain transportation such as the Jungfraujoch and the Schilthorn, but this is discounted. Your trip from and to Zurich will be covered up to Lucerne. Delivery to Germany takes only 3 days. This saves time on your way from Zurich to Interlaken, because you don't have to visit a ticket office to buy the pass then and only have to buy a ticket to Lucerne from a ticketing machine (you can start using your Regional-Pass from Lucerne onwards). See here for details on purchase options.