Gaming PC setup

[parlot1]

Hello, I would like some help setting up my new gaming PC. I very new at making PCs.
The setup I'm going for ( http://pcpartpicker.com/p/Nsr3Hx ) is to be able to run smoothly games such as Skyrim in high setting without having low fps and lag.
My questions are:
1. Are all those parts compatible? I know the web page says so but I'd like to be sure.
2. Will I need more RAM?
3. Do I need to upgrade some parts? If not, what parts can I downgrade so it is more economical
4. I know the PSU is very good one and probably too good for my need. Which do you recommend will be more appropriate for my setup?

Thank you and I sorry if this is not the place for this topic.
Ps: Non-English speaker

[eQuilibrium]

   
"
All generalizations are false, including this one.  "

[camerongray]

Not bad, just a few things I would move around a little to give this http://pcpartpicker.com/p/P7TXnQ costing a whole 5¢ more.  What I did there was drop the power supply down to 650w as 850w is way too high for a single video card system and then replaced the GeForce 670 video card with a GeForce 780.  The 780 is a current generation card whereas the 670 is from NVIDIA's last generation, the 780 is also significantly higher up the range of cards so will perform a lot better than the 670 for not a massive price increase (which is well offset due to that PSU).

To save money you could get an Intel Core i5 4670k instead of the i7 which won't impact your performance massively in games.  That said, newer games are starting to benefit from an i7 so if your budget allows it it is probably worth keeping.

16gb RAM is way more than enough, for gaming and most general computing tasks you'd be fine with downgrading that to 8gb.

Finally, why Windows 7?  There's no real reason not to go for Windows 8.1 nowadays, it just takes a couple of weeks to get used to it.

   
"
All generalizations are false, including this one.  "

Why have you posted that in two separate threads now?

[parlot1]

Update in the build:
http://pcpartpicker.com/p/BKk44D

[camerongray]

Looks great!  Only change I would do would be a slightly more powerful PSU like this for around the same price: http://pcpartpicker.com/part/seasonic-power-supply-s12ii620bronze.  While 550w is probably enough for a 780 in actual life, NVIDIA recommends at least 600w so I'd be inclined to go with that just to be on the safe side.

[parlot1]

I have chosen this PSU http://pcpartpicker.com/part/evga-power-supply-120pg0650gr
It's fully modular and 80+ Gold with the same price as the previous 3.
I think this is what I will go with. Thanks very much
Final build is http://pcpartpicker.com/p/9vtc4D