Looking for some advice on a few Nikon camera bodies. I currently own a D70S and I'm ready to upgrade to more of a "pro-level" body. Mostly shoot weddings (so, lots of low-lighting situations) and fashion/portraiture. Currently looking somewhere in the range of either the D700 or the D800. Quite frankly, I can't afford the higher level models. Have some good, prime lenses (which probably are not being fully utilized on my D70S at the moment). Any advice would be greatly appreciated!