Macbook air (2011) vs Macbook Pro (2011)

Hi,
I have been debating myself whether to buy mac book air or mac book pro (both 13” 2011 model)
What I want and need is :
1. must be light weight (I have Toshiba M300 which weights 2.4kg and it’s little too heavy to carry around)
2. battery must last long
3. must be quite while running (my Toshiba makes crazy noise)
4. not expecting to run Crysis 2 with high setting but want to have an option to play games like FIFA 12 with medium setting

Give me an advice….THANKS!!!!!

Lastly what are the must have accessories??