I have a scheme in the ideas bank to do a twin-engined Sea Hawk in the manner you suggest, although it there's rather more invloved than "just" shoe-horning a couple of smaller engines into it. My scheme (for a completely ficticious "alternative universe" aircraft mind you) had a fuselage stretch, Skyhawk wings and a mini-Buccaneer bomb bay.
Something I've though of to replace Nenes in all sorts of applications is an Orpheus with an Olympus fan on the front of it: the diameters and weights work. However, it's hard to see how you'd use it on the Sea Hawk (as opposed to say, the Attacker), since you also have to have an enlarged jet pipe for the bypass air.
Another idea is to backdate it to WWII: stick Typhoon wings, a tailwheel and a prop on it and claim that the Centaurus is amidships driving the prop via a shaft. You need to cut a lot more cooling intake/exhaust slots in this one!