Hi!
OK ! I see! I fly a sea level. But The power with those OS FS .26 is so great that I belive that an OS .30 and my 10x5 carbon props will work even at your altitude.
Monokote is ok but Oracover (Ultracote to you Americans) is much better.
My DC-3 is covered with chrome Oracover, first wet sanded on a sheet of glass with 1200 paper to get that aluminum look and then applied to the fuselage with an iron.
The text is painted using 2 part Sikkens automotive lacquer.
Dope and tissue or silk /nylon is still used but Solartex or Oratex is soo muck easier to use .

The elevators on my DC-3 are covered with Oratex and the side rudder with silk and dope.