The nicest looking to most people would be clear glass over bamboo laminations (if your question about bamboo included laminations over the cores) covering bamboo cores, but after that I personally would pick either clear or black glass over bamboo cores, depending on what looked best. I like the feel of bamboo cores better than Actionwood, but either makes a very nice core. Forget the speed claims -- there won't be more than 2-3 fps difference between any of the combinations you describe, and that could go any direction depending on the particular pieces of material and the way they work in the bow design you are thinking of buying. It's all good, just get what looks best to you. Your pick of the standard Diamondwood riser and black glass sounds perfect if it is what you think looks best. After all, it's YOUR bow!
Allan