OV Chipkaart or not depends on how much and what kind of travel you're planning. If the Zaanse Schans is the only trip outside the city, it's much better to buy a separate ticket. The OV Chipkaart costs you EUR 7,50 without balance for actual travelling. For travel within Amsterdam the GVB (the municipal transport company) has a whole range of options.
When considering the I Amsterdam Card you must realise that at the moment it doesn't seem to work for the Van Gogh Museum: you need to make a timed reservation and because of some hitch between the two organisations that doesn't work.
The Zaanse Schans is a popular outing for its proximity to Amsterdam and so can be crowded. It's an easy train ride, though, from Amsterdam Centraal (get a ticket to Zaandijk Zaanse Schans) and a 15-min walk to the area.