What are the best detection medias for cholera?
You should use Thiosulfate-citrate-bile salts-sucrose agar for the detection of all vibros, including cholera.  When cholera is presant, you should expect round, largish (not huge), yellow colonies.  This is the CDC recommended diagnoses method.  

Again this question might be better phrased "what are the best detection medias for cholera," or "what plate screens should be conducted when vibros are suspected?"