B&A-ers, your advice, please?

I say in a situation like this always go for the option that most challenges you. You don't learn how to write by doing things that are easy or come naturally. You learn as an author by pushing yourself to try new and different things. So go for the story that might be a little harder for you to write, and don't be afraid to end up injecting a little bit of you humor here and there into your story. There are some writers who write very serious material who are very capable of injection great humerous moments and witty commentary into moments that are otherwise serious and quite grave in nature.