As Karl mentioned, both versions of the Academy Spit XIV (high and low back) are inaccurate in various areas - the nose and mid fuselage being just two.
The old Hobbycraft kit can be found on e-bay and other places, and not too expensive. Whilst a little basic, it was, for its time, quite advanced, and goes together without problems, and looks like a Mk.XIV, although the canopy is typical HC, being thick and chunky, and needs replacing for a more accurate shape.
As Andy mentioned, a good kit of the Mk.XIV is needed, and Airfix should be able to produce one using their PR.19 as a basis.
The PR19 can be used, with little alteration, but needs the addition of the 'fighter' windscreen or full canopy, cannons and cannon bulges etc.