Pixhawk or Ardupilot Mega (APM2.6)

Hi guys,

I am trying to figure which board to use, Pixhawk or Ardupilot Mega (APM2.6) as I will be building an indoor fully autonomous UAV. I do not have any experience with UAV so I'm sorry if i asked stupid question.

I still cannot decide which is better and I am kind of confused by the information provided online.

hope that you guys can help me out.

Next, due to limited budget, I will not be able to purchase a laser scanner to detect obstacle in the room.

I will be using a camera and ultrasonic sensor instead. I have a question for this, Do I need an additional microcontroller to process the information received from the camera and ultrasonic sensor and convert to useful language to make changes to the speed of the 4 motors of the UAV depending on the scenario?

Or the Pixhawk and APM2.6 is capable of running the ultrasonic sensor and camera, received the output signals, process the information, convert into useful commands to make changes to the speed of the 4 motors of the UAV?

Thank you for your time