I don't exactly understand how your rafters meet in the first pic, and I'm not sure how the joinery is done in the same place in the second pic.
Carlos, If I were him I'd look at doing it like the frame we did where the king post extends to the top and the rafters are let into the kingpost as well as a ridge beam between bents is also let into the king post. The ridge beam(is that the right name since it is not continious?), is cut at the top with the angle of each side of the roof. I may be biased on that design, but is does seem more effecient and symetric to me, eh Carlos?
Check out the kingpost in the pics of this forestry forum post.
http://www.forestryforum.com/board/index.php/topic,29021.40.html