Hey Dave,
. I have been reading up quite a bit on lens, cause I got nothing better to do, and it seems to me that you might not need the VR with the 300 f/4. If you are planning on shooting mainly birds, you will most likely be shooting during the day, in the sky, with fast shutter speeds. IE: 500 and above. I believe there should be no problem handholding at those types of speed. I have done it myself (with lesser lens) and have no problem. The only time it becomes a problem is the early morning or late afternoon when the is insufficient lighting. Then reduced shutters do not make good stop action anyway.
And the 2.8 gives such a tight FOV that its hard to keep the whole bird in focus anyway. If you are truly concerned, what about a monopod? I actually works quite well and does not take up space like the full "Colin" ordeal. Well, good luck whatever you choose. Hope I made some resemblance of sense.