I know what you're saying. Among other things, Steve Vai is known as being a very precise player.
I have to disagree though. It might be a very good approximation, but it couldn't be exactly the same. As close as they might sound, no two things are ever exactly the same. We know this from science.
But going back to Gilmour, I don't think anyone should ever try to emulate someone's playing exactly. Learn what you can from them and formulate your own style.