I have been very happy with the Specialized Body Geometry soles. They have 3 different arches available. I am using the blue soles which, I think, are medium arches.
I needed to trim them a bit to fit my Sidi Genius 5 but they have been perfect. They definitely improve feet comfort during long rides.
They are a bit thicker than the original Sidi soles so make sure that your shoes will allow sufficient height clearance.