Hi Sifus

I am considering to upgrade ram for my laptop. But I need to know which type of Ram I can buy and also the maximum capacity my laptop can support.

Specs for my Notebook:
OS: Win7 Pro 64bit
Processor: i7 620M Arrandale 2.67GHz
RAM: 2 x 2GB DDR3 PC3-10700 (667MHz) Samsung 1.50V

Crucial Ram Scanner scan results said my laptop can only support maximum 8GB, but i read online saying that my laptop can support up to 16GB. Which one is correct?

Also, there are many type of ram in the market. Which is the best option for me? Crucial recommended me to use DDR3L PC3L-12800 1.35V. The specs looks different to my RAM.. is it ok for my laptop? Or any recommendation? Also, it there any difference between using 1PC 8GB Ram vs 2 PC 4GB Ram?

Thank you very very much...