I want to remove the cabinets over my kitchen sink and replace them with open shelving. The problem is that the cabinet opening spans about 6 feet and I don't know how to support the shelf in the middle so that it doesn't sag when I put some items on it. Also, there is a fir-down above it and I don't know if there's any kind of support up there if I wanted to support the shelf from the fir-down somehow. Does anybody have any suggestions on how to add open shelving to this space? Thanks!