I am buying a new Gaming PC

[d.emil]

Hello,
I am buying a new gaming PC and i need your experience to buy the best of them.
Here are some of them. This is a german website but you can see the statistics

This is my favorite but without windows. i have to install it.
https://www.notebooksbilliger.de/pc+systeme/gaming+pc+pc+systeme/products_id/371219

This have only 6 GB grafikcard memory. is it enough?
https://www.notebooksbilliger.de/pc+systeme/gaming+pc+pc+systeme/hm24+gaming+pc+hm245777

I have a 4k ultra hd monitor.

Or have you an another PC from this website?

 

[Shektron]

Both are good PC's. If you have a 1080p 60 FPS monitor, and you can upgrade the GPU in ~3 years or so, then the second PC is fine. If you want the GPU to last longer than 3 years, then the first one is better due to a better GPU.

If you have a 1440p monitor, or a 1080p 120+ Hz monitor, then the first build is the one to go with, no questions.

 

[d.emil]

I have a 4k ultra hd monitor

 

[Shektron]

Get the first build then, but keep in mind that a GTX 1070 is not enough for 4K gaming, so you'll have to lower the resolution to 1440p to get at least high settings and 60 FPS. At 4K, low-medium will probably get you 60 FPS.

 

[d.emil]

is the 400watt platinum power adapter good and enough from the first pc?

 

[Shektron]

Are you sure its platinum? I can't find it mentioned on the site anywhere that its platinum(which is probably because I don't know German). If you are sure that its platinum, then 400 W is still kinda bare minimum for a GTX 1070, and you should probably upgrade the power supply once you get the PC. A Corsair CX550 should do the job without too much expenditure, and so would a SeaSonic S12II 520 W.