The Wildcat was a “pure space interceptor” (non-atmo-capable?). They went into service around 2604, as we gather from an impromptu speech in 2634 by young Ensign Geoffrey Tolwyn:

Later we hear about it in connection to the Hurricane:

The kilrathi Kala fighter is presumably larger than the Wildcat; but the Wildcat's shields are superior:

The engines of the Wildcat ought to be located within the lower half of the body or under the wings, as Geoff manages to land a Wildcat under power, whose upper aft section was gone:

And after the war begins, and as Geoffrey Tolwyn crash-lands a wildcat, we learn about its cost:

Given that the Wildcat was a “pure” space interceptor means that it is definitely non-atmospheric, and therefore wouldn't need to be as aerodynamic as the Pioneer concept below, IMHO (Monk). This is precisely a ship one can safely go wild on without needing to worry about its aerodynamics; like a tie fighter with all kinds of extensions for maneuvering jets and armaments and sensors and what not.

UPDATE:
Maverick was just pointing out to me (Monk) that perhaps Pioneer's intent was to make their Wildcat seem like a precursor to the Hellcat, Bearcat and Tigershark lineage. If so, I'd have to say it looks to me more like a precursor to the Rapier. Frankly, I think the model would be perfect as it is, but as a model for the Hurricane. But in any case, my original comment, about the Wildcat being described by Forstchen as a “pure space interceptor” fails to address Forstchen's self-contradiction when he has Vance Richards, Tolwyn, Hawkins, and a number of other pilots fly off the Concordia in Wildcats to go and attack kilrathi troop carriers on their way to land on McAuliffe. Although the attack is done pretty high in the stratosphere, and with a stated concern for not losing too much speed —which, as explained in the book, they need to conserve in order to sling-shot around McAuliffe to get back to Concordia, given the Wildcat's limited fuel capacity—, some of the “banking” and maneuvers during that attack might seem to indicate a slowdown; unless Forstchen really meant that the ships changed just their facing direction, while moving more or less in a straight line. A slowdown is also hinted at by the fact that Tolwyn manages to see kilrathi troops dressed in camouflage spilling out of a transport he attacked… If he was flying at the Mach 30 or Mach 40 of a typical orbital velocity, even the transport he attacks wouldn't have a chance to register in his retinas, let alone individual kilrathis —unless he's using some kind of tracking telescope's view.