I would recommend staying away from BEC's. It is just to much of a risk. If something burns up in your aircraft you have now just lost the entire airframe. I've had it at times where a battery can come disconnected in flight or ejected then you have just lost your plane. With Lipo's being very inexpensive from China get a cheap 730 2 cell pack and a regulator and you will not have to worry.

Andrew Jesky