Possible use of Coax and Single Copter code

Hi all, I am very new to drone world. I have been doing some research on this topic but cannot see where anyone has further pursued my idea so I figured I would create a discussion to get some feedback and guidance. My team and I are looking to create two vehicles - one solely electric and one with a combination of electric and gas power. Both vehicles will utilize central rotors for the majority of thrust, and four rotors outside for position control. The end product will look something like this vehicle.
http://www.starlino.com/quadhybrid_intro.html

My question lies in how we might be able to implement existing copter code. It looks like using the Coax and Single copter code may be the best option.

The all electric vehicle would use two electric motors in the center for thrust (attitude control), with the four electric control motors for pitch, yaw, and roll. In comparison, the combined energy vehicle, will use a servo for control of the throttle to an internal combustion engine with counter rotating propellers. It will also have four electric control motors for pitch, yaw, and roll.
QUESTION: Is it possible to modify the single or coax copter to fit this need? If so, where should we start (I’m new to the role of development and my programming skills are limited)?
If you have any other suggestions for modifying/using other current airframes that may be a better fit those suggestions are also very welcome.

Thank you in advance… any and all GUIDANCE and TIPS are helpful. THANKS!

*edit: Also, as a note, we will be using the new Pixhawk2 as hardware!!!