Keith: I use LiFe batteries in my planes. Good choice. You might want to consider two 2200s, each with their own switch, and wiring. This provides two current paths to you RX (or power expander). If the servos happen to call for it, a LiFe can put out each amperage to melt connectors and switches. Multiply 3300 mah time the LiFe C rating. Two paths reduce that possibility.
Brian