What Laptop should I choose?

Recently I have been searching for the perfect laptop. I looked at Toshiba, ASUS, MSI, Sager, Clevo, etc. I cannot spend much more than $900.

My essentials are:
battery life of at least six hours,
a dedicated graphics card at least Nvidia 540 (though I would prefer higher like 555 or 640 etc.),
a 15 inch HD screen (14 is OK, and FHD is a bonus),
Intel i7 processor (i5 in a pinch)

My wish list is:
premium sound package (such as ASUS N series or most Toshibas),
back-lit keyboard,
8 GB Memory,
at least 500 GB hard drive at 7200 rpm,


I am almost sold on a Toshiba Satellite P750, but I am a little hung up on the screen quality. Any improvement on that without compromising the other things would be a great find. It might be pie in the sky, but if it can be found I am sold. I also have another question: Are Clevo laptops good quality? And are the AMD mobile graphics any good?