Building the first pixhawk X CLASS

Yes, I know, whats the point of building a 540mm quad with pixhawk. I have my reasons. Can it be done? I don’t see why not? I want to build a ultra long range 12s.
Im handbuilding the frame from carbon fiber 25mm tubing. I want waypoints, loiter/hover in place, RTH and GPS etc… I need a camera too (not sure if this is possible. … Im not SUPER familiar with this system but Im a total nerd and will grasp it within a week or so. But I dont know what modules / boards to get to make this happen. Ill also need the wireless transmitter for the Ipad pro so I can do waypoints and such on the fly. If someone could let me know what parts pack I should get. I plan on using big (3000 to 4000) low Kv (350-600) motors and either a 10s or 12S power system.
Any help would be great.

Looks like this forum is dead. No one replies to most of these questions