If dividing an image into multiple panels for framing, I would not use panels that are edge-to-edge selections. Instead, I would leave a gap approximating the panel spacing so that angular lines crossing images won't look distorted. The panels wouldn't have to be the same size and they could be staggered at different heights.
forum discussion: http://forums.dpreview.com/forums/read.asp?forum=1006&message=26371654