Get a guaranteed enlistment. Make the recruiter agree on what his job or duty is before any contract is signed. Otherwise he'll probably be on his way to an infantry assignment.
With the current mess going on across the world, overseas deployment is almost guaranteed.
I personally would have him talk to all 4 branches of service and see which one he likes. You will see that each branch has different things to offer. You will also see that some branches promise to give you everything and others promise to make you earn everything.
As far as "open contract" for the Marine Corps most of the people I know who were open contract when I was in acutally ended up in the air wing working on helicopters.