A123 on the ignition and reciever. If it were me I'd run a 1100 to the ignition and dual 2300's to the reciever.
Don't get caught up in the voltage checking, its something everyone that comes from nickel based batteries has to get past in their brain but let me tell you, its all I run in my big stuff. Fly a flight or two, charge the battery and see how much goes back in. It will tell you how many flights you can get, divide by two for safety sake. They charge so fast and easy at the field, and hold a charge forever.
No regulators, fast charging, no self discharge. Really no downside.
I get mine from
www.wrongwayrc.com
Also, if you have one of the older DA ignitions I wouldn't run it on 5 cells, and if you go A123 get a voltage drop down diode. Their newer ignitions will run on higher voltage.