P-51 Mustang Replica

[marianmadalin32]

I am currently building a full scale P-51 Mustang Replica . I want to make it flyable. I have all the parts(pieces) from the structure ready to cut and assemble. My question is: what material and what thickness should I use in order to make the structure (skeleton) both strong (to support human weight ) and light in the same time ? Steel or aluminium ? And what thickness ? 1, 2 or 3 mm ? Thanks again.