Yeah, you really should prioritise soldier gear over interceptors. I find the best way to go about it is get plasma cannons on you default fighters and not bother with the firestorm until *much* later. Those things take a *lot* alloys and elerium to build. At least wait until you have plasma weapons and titan armor before you start cranking out the firestorms, and even then, I'd only do one a month. Remember, there's no shame in sometime aborting an interception. Better the let a UFO go than loose a fighter. So long as you keep pumping out satellites, you should be able to prevent manage the panic levels.