Bill I can't say which mechanisms are the best, I have been using the "crush grind " mechanisms that you can get from a lot of places. I get mine from Woodworkers Supply. I have used 10 of them so far with good results. I like them because they don't have the hardware showing like some of the other brands. I think it depends on the look that you or your customer is looking for. They come with either a shaft that is 10" long that you cut it to the length that suits your design, or they also make a shaft-less mechanism.
Chuck