I have had a Nikon D70 since late 2004, and I am considering upgrading. I still love it, but I am going to a bird photography workshop and I was thinking about upgrading to either a new 18-200mm VR lens(to use with the D70) or a D300s and use the 70-300mm(non-VR) lens I currently have. Which would be the better upgrade? Obviously I know which is the cheapest, but I would like to get the most for the money. This will be my first try at bird photography. I also like to shoot landscapes.