I was wondering if anyone had any recommendations for my particular situation: We will be flying from Boston to Istanbul (with 1 stop in Europe) with a 3.5 year old and a 14 month old (heavy guy). We've done this before w/ 1 kid only and had varying experiences with Lufthansa and Iberia. When we flew Lufthansa, we got a bassinet at bulkhead for our 10 month old, which was great. With Iberia, we brought car seat for our then 2 year old son, and the seat in front kept squishing his legs and we had to literally fight to get the seat on the plane.

Any recommendations on:
-Which airline is best with this set-up?
-Is it worth it to spend another $1200 and buy a seat for the 14 month old?

Thanks in advance...