I am going to be building a scratch build soon and would like to know. I am designing a top wing trainer where the wing panels are going to slide into the fuselage. In doing this the wings are going to be straight (no dihedral), which I guess makes it a sport trainer.

Question is, because it is a wing with no dihedral, does it need to have ailerons? I heard that these type planes do not have the same rudder control as a plane with a dihedral. Is this true? If it has the same rudder control can I get by without ailerons?