Variants of existing fighters that would be competitive:
Bf109G-10 An attempt to consolidate Bf109G versions this fighter has performance below that of the K-4 and entered service after the K-4.
Bf109G-14/AS This version had a high blown engine and much improved handling at altitude.
Ki-84-Ib This version of the Ki-84 has four 20mm Ho-5 cannons and possibly a slightly uprated engine. It might be a low end perk plane.
Spitfire Mk XII The first Griffon powered Spitfire, low blown Griffon IIB rated at 1,730hp, clipped wings.
Variants of existing fighters that would be semi-competitve:
Bf109G-6/AS This version had a high blown engine and much improved handling at altitude.
F6F-3 Earlier version of the Hellcat with slightly worse performance
Fw190A-9 An improved BMW engined Fw190.
Ju88G-7 Late fighter version of the Ju88, fast with good firepower.
Ki-61-II A slightly uprated Ki-61.
Ki-100 A slightly uprated Ki-61 with a radial engine.
Mosquito Mk 30 Final fighter version of WWII, high blown engines, more cannon ammo, no machine guns and no bomb bay.
N1K1-J Older version of the N1K2-J with mid-wings, less ammo and a different tail.
Seafire Mk III The main prodution model of Seafire with 1,220 built, powered by a Merlin 55 or low blown Merlin 55M. First coplete carrier adapation of the Spitfire.
P-47D-22 A version with improved performance and ordnance over the P-47D-11. (I am mystified why this keeps getting requested)
Competive variants of existing fighters that debatably meet what are understood to be the inclusion requirements:
Spitfire F.21 The final Spitfire of WWII and the only WWII Spitfire to get the redesigned wings, was powered by the 2,035hp Griffon 61. Saw only limited combat, sinking a German minisub. This fighter would be perked.
Yak-9UT Yak-9 powered by the same VK-107 engine in the Yak-9U but armed with with two 20mm B-20 cannon in the cowl and a 23mm NS-23 in the nose. This may be a perk fighter.
Competitve variants of existing fighters that do not meet what are understood to be the inclusion requirements:
Fw190D-11 Armed with two 20mm and two 30mm cannons in the wings and powered by an uprated engine this fighter might be perked.
P-51H A lightend, cleaned up Mustang. Very fast, but missed seeing combat though it was in service with fighter squadrons before the war ended. This would be a perk plane.
Seafire Mk XV The first Griffon powered Seafire, low blown Griffon VI rated for 1,820hp at 2,000ft, it had poor deck handling.