Tru Cool are the most effective coolers made. They are like a radiator, exposing the most amount of oil to air flow.
Something that a tube and fin style cooler just don't do. Quality tube and fin coolers will have what they call a "turbulator) in each of the tubes. The object behind this is to tumble the oil as it pass through each tube and uses a "skin effect" to cool the oil. Cheap tube and fin coolers will have a turbulator in only the two tubes you attach your hoses to. That being said, true cool is the better style of cooling. And yes, you can get them with threaded connections, just get one of their engine coolers. Same cooler as the transmission cooler, just has thread connections.