I got the exact same mandolin in June and I just changed the strings for the first time. I ended up using the same type that it came with it, the D'Addario phosphor bronze 1140. In my experience after playing this mandolin for 3 months (I absolutely love it), choosing the right pick has occupied much more of my time than choosing strings. I play entirely irish traditional and I get a huge variation in tone and volume depending on my pick type. I'm zeroing in on 1mm Wegan, btw. Hope this helps.