As a minimum:

Two 2200Mah batteries reciever, and one 1200 Mah ignition. Each through a separate switch, as you stated.

NiCads are fine, but a little heavy - 4 cells direct or 5 cells with a regulator. Nimhyd are a little lighter, and Lithiums will be very light.

The sky is the limit from there, but these are the minimum recommendations.

CJ