You guys are looking from your own point of view. It is much different for him to go to a US customs officer as as Muslim man to make a cash declaration compared with you as an American citizen. A certain percentage of the customs officers are going to be looking to see if they can get their hands on his money if possible, so he should do anything he can to avoid having to make that declaration.

My recommendation: $8500 cash (not $9800!) and the rest in a Bluebird. It may be that in his home country he doesn't have ready access, but he can spend the money online and when he goes to neighboring countries. It is likely by the fact that he is posting his story here that this would not be a difficult spend for him.