Ok, so unfortunately I don't have 2 trees at appropriate distances in the yard. I live in Florida, so no basement with rafters. And from all the info on the forums (and a few hand calculations), the stress on the rafters is a bit questionable.
So what to do?
This is what I came up with. An 8 foot 2x4 (which I just happened to have in the garage) as a stiff ridgeline to take the compressive stress. This way the only stress on the eye bolts in the beam is a downward force of my weight. (ok, a little outward force because the eye bolts are not directly above my attachment points)
I'm going to clean up the suspension a little, and maybe a longer 2x4 to allow for a more natural hang. But all in all, a good test bed for my DIY hammocks.