I was also thinking of Plexi or Lexan, but I was worried about the optical quality. My other option is to use 2 filters to provide better resistance to impact.
I am not to worried about the body of the camera, I can wrap that if needed, but the end of the telephoto lens has me nervous.
"And gentlemen in England now a-bed Shall think themselves accursed they were not here, And hold their manhoods cheap whiles any speaks That fought with us upon Saint Crispin's day."
William Shakespeare Henry V.