Post your pictures here; may be can ID it for you. I'm an amateur birdwatcher, myself, although I always have trouble telling sparrows apart at a distance...
My beliefs about reincarnation are complex and probably different than what you'd immediately think of when you think "reincarnation," but suffice it to say it's also a part of my belief system. What puts you back in the mind of the your beloved friend and helps you to get past the tragedy of the death... why shouldn't that be a comfort? Doubtless, there are aspects of Bird's spirit in many places (especially around your home), and if this is the one that reached you, the beacon, of course it's a message. I'm glad for you.