And using a lipo for a receiver battery is not such a good idea for a multitude of reasons:
1. the voltage is too high for most servos
2. when (not if but *when*) you forget to turn the plane off you ruin the battery.
3. like all Lipos, they constitute a degree of fire danger when charging so need to be removed from the model (inconvenient!).
You're far better off going the 2S A123 path because they're bullet-proof, safe and a far more acceptable voltage.
You can build your own 1100mAH A123 packs buy purchasing 2 cells and a 150mm servo lead from HK then doing a small amount of soldering. Total cost ** about $17. Well worth it!