I need a Laptop for Digital Art (digital painting, 3d programs) etc.

I am considering either the
Dell Studio XPS 16 15.6-Inch Laptop

http://www.amazon.com/Dell-Studio-15...4860596&sr=1-2

Or the ASUS Republic of Gamers G51JX-X3 15.6-Inch Gaming Laptop

http://www.amazon.com/Republic-Gamer...ref=pd_cp_pc_0

Each of the laptops have a fundamental flaw, the Dell apparently heats up and get Very warm or even hot, the Asus has a very short battery life (about 1 h 15 min) or (2 h 17 min) with a bigger battery.

The laptop will be a desktop replacement and I will also take it outdoors doing Digital landscapes from life which is why heat or short battery life may be a problem when digitally painting (using a lot more CPU power).

Some one also suggested to me that I get an Apple MacBook Pro but I am not a mac fan. I prefer to stick to PC.

Any advice welcomed, thanks.