Another vote for a two man tent. I occasionally tour with a Hennessey Hammock; but on long tours I take a REI Quarter Dome T2+. Being able to keep your panniers inside makes a huge difference to comfort. It's nice to be able to access all your things, especially when it's raining. Don't think the vestibule will protect your gear. I've woken up to find my tent sitting in shallow pools. Had my panniers been sitting in the vestibule, they would have been soaked.
Yan - I've really been looking at the Hennessy hammock myself. What kind of downside do you find with a camping hammock, and how does it compare to the tent? I'm just looking at short weekend+ rides(Silver Comet next month, Katy Trail in Sept), and comparing.