Upload & Sell: Off
At this point, I don't accept many weddings, but I have shot enough to have some thoughts.
It depends on your vision, whether you need a long zoom-some people see in wide angle and hardly ever use it-I couldn't live without it! Maybe consider the new 70-200 f4, if the 2.8 is too pricey. You will save a lot of weight, also.
You absolutely need 2 cameras, several lenses, and multiple flashes-things do break! (usually at the worst time!)
I would not go with something as old as a d90 because the images will have a different look, but that may not be a problem. A d700 will serve you well for a long time.
Mac vs PC--prepare for war!!! I have had 11 PC's and 3 Macs-I will never have another PC! A basic imac and some outboard hard drives will do everything you need and do it well. There is a photo/artist who does many hundred layer productions, (I am sorry to have forgotten his name) on his Imac
This is a totally personal observation, but I hate lightroom! Go to the forums and see just how many problems people have with it. Nikon Capture NX2 will give you wonderful images with very little work. (Prepare for the deluge of nay-sayers!) I very seldom open photoshop, any more. Despite what some will say, I have used it on many thousands of images without so much as a hiccup! Nor has it ever lost my entire library, as LR did.
Save some money for emergencies and unexpected needs.
Good luck and enjoy your photography.