Warukyure :
Those 2 components are much higher than than even the recommended specifications for Unity from even Ubisoft. While in theory it should be able to play 1080p and probably even Highest settings. Ubisoft has been know to be (REALLY REALLY) bad at PC optimization for their games so it is still possible to have frame rate drops occasionally.
Hard to tell since the game isn't out yet.
For the record the recommended specs for this game is
i7-3770k
GTX 780
i have 2500k(4.0 ghz) 8g ram and gtx 970(1478 ghz oc) 2560x1080 (ultrawide, typical 1920x1080 may see some performance increase)......on ac unity everything as high as it will go i get 25-35 fps.
shutting off aa effects section and leaving everything else maxed, i get 55-65 fps
to put this in perspective, i get 115-135 on bf4, everything maxed
Some tests have shown that the GTX 970 matches if not out-performs the GTX 780 on some game benchmarks.
Food for thought:
The PS4 has a 1.6 GHz octa-core CPU and a video card equivalent to the HD 7870. It plays the game at 900p and 30 FPS. The i5 you chose is MUCH MUCH faster than the CPU that the PS4 has and the GTX 970 runs laps around the HD 7870. (Btw not hating on the PS4, ill probably buy one black friday)
Thanks man!

Cuz the shop told me that it is not stable, then it makes me worry for the decisions.
Then, they also told me 500 W is not enough to support the system, it may cause lag, is it true?
My specs:
1) i5 4690
2) GIGABYTE B85M- D3H
3) Kingston Fury DDR3 4GB 1866MHZ (4GB x 2)
4) WD Blue 1TB 7200 RPM
5) Liteon 24x DVD/RW
6) CM N200 Casing
7) Asus GTX 970 Strix 4GB
8) 500W SILVERSTONE ESSENSIAL 80 Plus