I'm not sure of the price (please enlighten me on this), but half a year ago I was deciding on buying a flash aswell. I went for the SB-600 because if I needed a flash commander unit in later years I can buy a SB-800 (little did I know they have SB-900 now) and I would be all set.
If SB-800's price is cheaper than SB-700, then wouldn't SB-800 be better?