I'm having some problem figuring out the size of my ridge beam (or maybe a parallel cord truss if the beam ends up being to big)

I attached pictures to my Google picture website which you can visit below

http://picasaweb.google.com/tristan.burm/Tellico

The span of the area that does not have an upstairs is (2x) 26 feet (clouded as number 1) the span in the opposite direction is divided into 3 beams (2x) 18.5 feet and (1x) 26 ft (clouded as number 2). The two beams in the open space will be connected to the other 26 feet beam (hopefully my bad explanation and the picture can help you out)

I’m wondering if anyone can help me design the beam size for this type of ridge

Thanks in advance for all the help