We need more info. Are you planning to travel a lot in Switzerland ? Going to peaks like Jungfraujoch, Schilthorn, Titlis ? Any day trips from Milan ?

Also consider the Swiss half-fare card (120 CHF for a month) + half-fare tickets/saver day passes. Quite good value in the Jungfrau area where you only get 25% discount with STP or Eurail.

My game plan is to Land at Zurich, stay there for a day or two then to take the train to Luzern, visit Mount Palatis and Titlis, then I am off to Interlaken, visit Jungfraujoch area then im off to Milan and stay there.

Okay then since your focus is in Switzerland, I'd suggest either :

- Swiss Travel Pass : ticket valid everywhere + 50% discount on Pilatus, 25% on Jungfraujoch, Schilthorn

- Swiss Half-fare card (120 CHF for a month) : half-fare discount everywhere, including to Jungfraujoch. Buy half-fare Saver Day Passes in advance (on days you know you'll travel a fair bit) and (half-fare) point-to-point tickets as you go. This is likely the cheapest option but it will require some effort (manageable)

Both options are valid until Domodossola, the border point. Then get a ticket on trenitalia.com for the last bit to Milan. Due to works in Italy less trains are able to run during weekdays : you'll either need to wake up very early, arrive in Milan in the afternoon or make a detour via Novara.

Download SBB app : it will help you with timetables, tickets, etc.