The main ones are durso, herbie, bean animal. The herbie and bean animal are "full siphon" drains, meaning that while the drain is in operation, there is minimal air in the pipe thus eliminating the gurgling sound you hear with durso drains. It seems that most people will opt for the bean animal over the herbie, if given the option. In contrast, durso drains are designed to allow a substantial volume of air to mix with the water as it enters the drain. This mixing is in itself not a bad thing, however, once the drain water exits the pipe in the sump, it does so with large volumes of air. This creates varying sizes of bubble to enter the sump and can be quite noisy. The sound can be minimized by using the straightest run possible from the bottom of the tank to sump. Also, the larger the drain pipe relative to the volume of water exiting will minimize the variation air volume being trapped by the water flow therefore minimizing gurgling. In your case, it would benefit you to use 1 1/2" drains from the bottom of the tank to the sump, as opposed to the 1" diameter bulkhead. This may not immediately make sense, but once you see a durso with a relatively small drain pipe in operation it would be clear. I don't have any schematics for the drain types but they should be easy to find here if you search for the terms.
