I would do a column of 5 landscape, a column of the 4 portrait, a column of 5 portrait, a column of 4 portrait, and a column of 5 landscape. Columns 1,2,4 and 5 should be the same length. The longer column would be in the center. Wait, I just rethought it. Switch columns 1 and 2 and then switch column 4 and 5. Should work out and be interesting if you use the right sashing, etc.