I've got a Toshiba KIRA V63, which is basically exactly what you want except with an i5 processor. If I put the screen backlight to 11% (which is readable for me when I'm in the library or whatever) and run powertop, I can get 9 or so hours of real work done on the battery (Ruby on rails for the most part, Chromium and Emacs, judicious use of wifi).
I highly recommend the recent mobile i5 processors. They are ridiculously low power and amazingly fast. I really do not want for anything.
Now you almost certainly can't buy a V63 where you live (only Japan and even then I've heard Toshiba are getting out of the business), but this is the spec I recommend. The 1080p screen is the most important thing for battery life and performance. Don't get a higher resolution screen if you want to do a full day's work away from the power mains.
I absolutely love this machine to death (and take it with me everywhere -- even to the onsen).