If budget is tight and your main aim is street photography, go for the lower-end bodies. Several years ago, I picked up a used D3100 and 18-55 for ~$400 and used it for street shots. Simple, light, fast and quiet. That's all you need. The other great advantage -- smaller setup is less obtrusive. Worked for my type of street shooting, dunno about yours.
Between the D700 and D7100, probably the D7100, for the reasons above. Never used it, but I used the D700 for event coverage for years -- big, heavy and LOUD shutter.