Firstly I migth presume you have got this sorted by now, but if not, heres a few pointers.
1/ if you are using 2 seperate esc’s for individual motors,
a/ are you using a seperate battery for the recievey supply?
if NO, then it might be a conflict with the esc’s trying to act as “master” controller, you may need to disconnect one “power” wire to one of the controllers.
2/ i then see no reason why seperate esc’s should not work to control each motor, just remember to find correct channel for each on the reciever.
3/ helicopter type only means the throttle stick is right one, whereas boats/cars is left stick.
but being as you are using both for throttles anyway, theres no difference for you, apart from the one stick being spring loaded to centre off, but speak to radio supplier and he can supply you with a centering spring, so you then have forward/reverse on BOTH sticks.
make sure you remove the batteries in the reciever when you retfo fit this spring and lever, but once you power the transmitter back up, it automatically “adjusts” its controls for “centre off”, you dont have to do anything else.
let us know how you get on.