When I used to have my Nikon D80, I mostly used my 17-135mm. That was both because of the range and wide angle. Now that I have the D700, what would you guys recommend for a lens that would be compareable to the 17-135? I am willing to spend around 800 max. I'd rather have good lenses to start with than to switch later on . . . Oh, I have to mention, I need a fast one !