Take the D800. Morocco's geography is spectacular and you'll be pining for your Nikon if you don't take it.
You might consider a strap that doesn't say "STEAL ME!" like the stock one does. DSLRs look pretty much the same to the uneducated and a bit of black electrician's tape over the various logos on the camera will help conceal its identity.
If you have a big lens installed, that will attract attention, but if you're worried about your gear in the markets, you probably won't want a big zoom at those locations in any case
Use common sense about leaving it around anywhere. Besides, if it's not with you, you can't shoot.
Take anti-dust precautions. It's a dry, dusty place.
It's also a target-rich environment for photographers. Have fun.