I had an old Kyosho 70mm fan that I thought I could use but that didn't work out either. The servos I picked up are Tower's new 9gram, 17 oz servos that are about the same size as Hitec 81's. Still waiting to order the motor. I believe if you use the E=flite recommended ESC you don't need a separate BEC. Just my thoughts.
I picked a 60A ESC with BEC and I'm going with that.