For rattle can paint, I heard Tamiya Insignia White over a black primer for the X-Wing, which looks pretty "Star Wars White Ship" to me on my MPC X-Wing. I was not thrilled at how many cans I needed for one stupid X-wing, and I would be terrified of the cost of base paint alone going that route for a something this big though.
.
Side note, I saw the Disney diecast ships yesterday, including the Falcon (bought the Star Destroyer, and kicking myself for not picking up a Falcon, even though the paint is actively, aggressively, in-your-face bad, and somehow almost all of them had damaged radar dishes, including CHUNKS missing out them - figure that one out) and, is it just me, but between this one and that Disney one, do the new Falcon toys coming out suddenly seem to be using some pretty reasonable dimensions in comparison to previous offerings?