4*4 or 2*8 GB doesn't matter. 16 GB will probably be enough forever. The speed difference is only ca. 1-2%. As a rule performance gain up to 20% can hardly be felt.

CPU performance is not that important. The vast majority of the games are graphics card limited.

SLI graphics cards are a risk. I wouldn't buy one. Single chip cards are fast enough, especially for a middle resolution like 1080p.

If you want to connect the notebook to your TV make sure it has HDMI and find out how to get the sound out. It's not a given that sound is automatically passed on to the HDMI jack. Maybe it is, maybe it's not.