Going through my paints...Vallejo's Terracotta is indeed a good option, it is darker than their other oranges in the Game Color line. Also, I could see their Game Color "Parasite Brown" being a good highlight color for the Terracotta.
You have options in the Vallejo Model Color line as well...and Abington BG carries them. "Orange Brown", "Medium Fleshtone', & "Red Leather" are pretty convincing.