i pressed the wrong key, still had something to tell..... 
well don't be frightened by the code, it's only a matter of PID stabilization and then you'll have to build a good state manager to keep a minimum level of security, how are your pilot skills? quads are difficult to fly if the stabilizer is not correctly set up
last but not least, the DUE is overpowered IMO for what you have to do, i am OT here 'cos i am building my quad with an UNO but i own a DUE also and im doing some tests to be able to exchange the controller when i will try building the autopilot
as far as now, just to fly it safe under RC control 16 MHz seem enough for me, let's see if i'll manage it