dudw no matter what you need to stick to one thing(EG the out rigger is the best bet) ok now you need to get a rechargable battery 7.2 volt stick pac at a hobby shop thay go for like 15 bucks or less then get the charger and you will be set then the 700 motor

ok this is what you do take the drive shat so that it is "almost" level with the hull and the prop need to be like 1-2 inches away from the back then get somthing to mount on the back of your boat that is about 1/2 inches away from the prop and mount the rudder then get the servo arm out the back to conect to the rudder

i now this isnt fancy but it seems to me that you are on a buddget so this is the best way for it unless you can find the funds else wear!!!!!