Can you provide more clarification on the damage and repair necessary?
Both of them have aluminum skins and Bundutec appears to be bonded in a single sheet with some backer (luan or azdel or...?). And I'd assume, maybe incorrectly, that the frame, foam, and skins are a bonded unit on all of them. Damage to the outer skin can be dealt with easily enough (bondo), but if the wall structure is damaged how would that be "fixed"? I suspect it would be weaker than the original.
I think composite would be easier actually, since impact damage would most likely only effect the outer skin and foam.