As an example of how it would go (keeping the international flavour for now, which can be changed if the majority wish)
Mitsibushi A6M ‘Zeke’ (Japan) vs Curtiss P-40 ‘Warhawk’ (USA)
A6M
Max Speed - 351 mph (565 Km/h)
Service ceiling - 38517 ft (11740m)
Range - 710 miles (1143 km)
Rate of Climb - 19685ft (6000m) in 7 minutes
Armament - 1x 7.7mm (0.303in) and 1x 13.2mm (0.52in) MG in nose
2x 20mm (0.787in) cannon in wings
2x 60 or 250kg (132 or 551lb) bomb
Carrier borne fighter used by the Imperial Japanese Navy from 1939 until the end of the war. It was extremely agile, outclassing the Buffalo, Hurricane and Warhawk fighters it faced at first. The agility came at the price of being very lightweight, with virtually no armour included in the design.
P-40
Max Speed - 378mph (609 km/h)
Service Ceiling - 38000 ft (11580m)
Range - 240 miles (386 km)
Rate of Climb - 15000ft (4570m) in 6.7 minutes
Armament - 6x 12.7mm (0.5in) MGs in wings
Up to 3x 227kg (500lb) bombs
Used by the USAAF, RAF and many other allied nations from 1938 until then end of the war. Very heavy armement of six 50-cal machine guns, but slower than many newer fighters, which eventually replaced it. Gave good service in the Mediterranean, North Africa and the Far East.
Everyone then has a couple of days to give their opinion about each aircraft and cast their vote for the best. The opinions should be based on purely the aircraft (ie assuming the pilots are of a similar skill and experience and that the combat is completely even, with no advantages).
Eventually we get to the grand final and the winner takes the title of official WW2 in colour best fighter