Something along these lines sounds like what you are after: -
http://www.ebay.co.uk/itm/9-6V-2500m...item5405e02ed7
You'd select the Futaba connector option.
I also use lipo, but if you havn't got the charger, then that'll be no good to you. A 2500 Nimh like the link is going to give ample transmitter on time anyhow.