Best airflow config for a Corsair 600T

[redlight]

For my first gaming build I'll be getting the Corsair 600T, 4670k overclocked with an AIO liquid cooling system, and an overclocked GTX 770 or 780. The 600T comes with:

• ■ 200mm intake front fan (only room for 200mm x 200mm x 20mm
  ■ 200mm exhaust top fan (room for 2 x 120 mm)
  ■ 120mm rear exhaust fan

The liquid cooler should take care of the CPU, but the 120 mm rad + fan will occupy the rear exhaust, and as I'll be overclocking the GPU, great cooling is definitely needed. I can move one of the drive cages for more air flow from the front. Will replacing the top 200mm exhaust fan with two 120 mm fans improve the cooling of my GPU? Ignore the sound increase. Here is a good example of how my build may look:

If you guys have any ideas, let me know!

 

[coastie65]

Should be fine. I have a 200 intake in front and two 120mm's in top for exhaust plus the 120mm in back also exhaust. My thught is that I may be a bit close to negative air flow and probably be positive air flow for better cooling.

 

[redlight]

Should be fine. I have a 200 intake in front and two 120mm's in top for exhaust plus the 120mm in back also exhaust. My thught is that I may be a bit close to negative air flow and probably be positive air flow for better cooling.

Are you using the stock 200mm intake? Also, how can you ensure positive air flow?