There were about 75 2 seater P-38M nightfighters built, a batch of 2 seater TP-38L trainers, and some weird variants , one of which put a bombadier in the nose, and another of which had an observer in that position. Then, there was the twin cockpit version used to test a pressurized cockpit...
I'll spot you the single engine P-51 since as I recall the twin engine version had a different type designation, and may have postdated the war.
The Lockheed P-38 Lightning was one of the best-known Army Air Forces fighters that flew in World War II. It was already in mass production before the war started for the United States, and production lasted until 1945. With a wingspan of 52 feet; a length of 37 feet, 10 inches; and a height of 9 feet, 10 inches, the P-38s had maximum speeds ranging from 390 miles per hour for the basic P-38 to 414 mph for the P-38L. Except for the M model (a two-seater), all the P-38s were single-seat pursuit and long-range escort aircraft.
North American P-82 "Twin Mustang" at Muroc Army Air Base, California. Official flight view of the "Twin Mustang", the Army Air Forces long-range fighter. Powered by two 12-cylinder Allison V-1710 engines, the P-82 is capable of a top speed of over 475 miles per hour. Rate of climb for the aircraft is over 5000 feet a minute. Standard armament is six .50 caliber machine guns, but the P-82 can also carry eight additional guns in a special center nacelle.