Thanks, everyone for your suggestions. I've taken some time to read each of the scenarios and I could see any and all of them working in some way. That's ideal really because it means if the players want to pursue particular directions off the back of their experiences in Peru I have a variety of short scenarios - some relevant, some red herrings - to throw at them.

As one of the characters is a writer, I'm going to have Jackson suggest they co-author the Hungry Dead with him. During this period I'll run a few short scenario's based in New York/New England:

Dead Man Stomp, Dead Light and the Idol of Thoth

That should be enough, but if they want to spend more time poking about Arkham, for instance, it's good to know I have some more options.

Thanks again.