Upload & Sell: Off
Landscapes - D800
Models - D700/D800
Family pics - anything, you can buy PnS for that
Depends how much you like each of that. D800 gives benefit to everything (yea even family pics, you can create some really good crops from that, if you will have really good lens and light). Downside is, that 36 mpix RAWs are sorta on bigger side and you need a LOT of HDD space. And good PC. And good light as high ISO aint that beautiful on per pixel level (means no tight crops on higher ISO). Actually I dont like per pixel noise at low ISO at all from D700. I guess Im minority, but I think that at base ISO, camera should have squeeky clean image quality.
D700 was and I think still is best bang for bucks. I would go with that as 12 mpix is easy to handle, its very clean on pixel level, have nice colors which degrade only very slowly with higher ISO. Yea and it doesnt make my hand ache. (good ergonomics.. D800 is step in different direction in this) And its sorta "cheap".
Yea and if you prefer high ISO, it doesnt get blue in shadows and doesnt have too much of hot pixels.
Its your call. For me I can say that as step-up from D3000 is D700 good choice.