Soldato
I know, i have 2x 29's at at work, one on top of the other
Well, having a 27" in portrait, I can safely say that having the two 34"s stacked on top of each other (as long as the bottom one is very close to the surface of the desk) should reach roughly the same height, which to me is fine, as the top one will just act as a secondary (Skype, and the like)