We are also vegetarians and feed our children organic homemade food. My daughter is now three and my son is 10 weeks. One of my favorite on the road food items for Nora was beans. I would take canned black beans and cut them in half (crazy, but I was nuts about her choking). Those are a good protein source (and if you could pick up some rice that would be great). Another idea for eating out is eggs.. Nora loved fried eggs. I found Earth's Best baby food was good for on the go too.
I travel a lot with my children (by the time my daughter was one she had been camping in Colorado, and had been in 9 different states). I remember that feeding Nora when she was in that transition stage was one of the stresses I had. Beans, blueberries cut in half, rice, eggs, canned peaches and mixed fruit, cheese sticks at room temperature cut into tiny pieces, and the jar baby food were staples for traveling.
Good luck and have a wonderful time!!
E.