I still use my 9-C but may upgrade to the add on 2.4 in the future., when the 2.4 systems became the must have item you could buy A nice used 9-C for about 150 bucks all day long.
With the 9-C and an 8 ch RX ch #8 is the default for the other elevator servo, you just have to plug into 8/B and actavate it. Two aileron servos are ch #1 and/or ch #6 or #7. Most planes I set up A single rudder servo but on my newest plane I'm setting up right now I have two servos for the rudder and have them set up like two elevator servos with 4-40 rods doing A push pull, for this I set up the servos with A match box but the radio can do it too. The match box was just an easier set up and I had A brand new one in my shop that I had never used, figured now was the time to dust it off.
Sounds like maybe you should go visit the Futaba site and read the instructions so you have an idea about what this radio can and can't do. This site will also tell you about using two batteries but most people just use A Y harness and plug into one slot or use two switches and plug into two slots.
Read up on this stuff then ask the questions here, you will understand things better that way.