I want to use in all these 3 areas
1) studio
2) Runway
3) Outdoors
1. Studio: Low-ISO, high-DR bodies like the Sony A900/850 or Nikon D3X. Good AF in low light too.
2. Runway: Body and brand doesn't really matter. But I suggest having a 24-70 f/2.8 and a 70-200 f/2.8.
3. Outdoors: Any camera will do well. Having a 24-70, 70-200 and a 50 f/1.4 or 1.8, 85 1.4 or 1.8 or 135 f/1.8 or 2.8 lens will be handy.
These are photography basics. You obviously have no knowledge or skills, so I suggest you get the cheapest budget body first and grow from there. Spending $3k on top equipment with poor skills will still result in poor pictures.