Our Wildcat is more of an F4F-4/FM-1 hybrid. The FM-1 was essentially a lighter four gun F4F-4 built by GM but was nowhere near as light as the F4F-3.
If we ever get an AH Beaufighter logically it would be the Mk X and maybe the earlier Mk VI as well. The later variant was heavier, had more powerful engines, centimetric radar and belt rather than drum fed cannons. The two marks couldn't be merged as AH can't change engine power or armour on a single variant. The Mk X could be merged with the Aussie Mk 21 though, this had four 0.5 inch guns in the wings instead of six 0.303 inch guns and carried US HVAR rockets instead of the British RP-3 rockets.