RV Repair: wood vs metal, wood studs, metal studs

Question
Am completely rebuilding a 1971 18' wood frame aluminum skinned Elkhart Traveler travel trailer and wonder if metal studs(the kind used in home construction, if dimensions are correct)can substitute wood to make lighter, without sacrificing structural integrity.   Plan to use 1/4" poplar plywood on interior walls and ceiling and 3/4" plywood for the floor. My guess is that I'll have to use wood studs for the floor, roof, and front and rear curved sections.  
I appreciate any feedback you can offer.

Answer
HI ROB
IN A REBUILD THERE REALLY ARE FEW RULES WHEN IT COMES TO MATERIALS.
LIGHTER IS BETTER..BUT STRONG STILL COUNTS.
THE OEM DIDN'T WANT TO MAKE THEM TOO HEAVY OR TOO EXPENSIVE SO THEY USE LIGHT WEIGHT (CHEAP) MATERIALS...BUT IN A RE-MOD, YOUR THE BOSS. WOOD IS MUCH EASIER TO CUT TO SIZE AND THEREFORE MY FIRST CHOICE.

THOM