D700 with 24-70 or D800 with cheap mid-range zoom?

I was wondering if any of you could give me some advice about purchasing a new camera. I currently own 2 Nikon lenses (50mm 1.8G and 70-300mm 4.5-5. 6). I did previously own a D700 but had to sell it when I started school because I really had no time to use it. I am now looking to purchase a camera again and am wondering which of the 2 routes (as stated in the subject) I should take.

Thanks