Well you dont have a GPU listed for starters. Second, youre not going to build a small rig that plays Metro on max settings. That along with Crysis 3 and a few others are the most demanding games on the market right now. If maxed out Metro is what youre after, youre gonna have to cough up some more cash. Heres the best, most budget friendly rig I can come up with thatll still give you playable frame rates on pretty much anything out there with max settings with the exception of some lowered AA.
I went AMD because the FX-6350 is the best gaming CPU on the market dollar for dollar right now IMO. It overclocks very well and will work just fine at 1920x1080. The GTX770 is enough horsepower to play anything at 1080 at maxed settings. You might have to drop AA down to the lowest setting on games like Crysis 3 but thats really no big deal and youll likely never notice the difference in actual game play. Usually its not until you show slides side by side that you can really tell the difference between different AA settings but lowering it really saves a ton of frames. The motherboard is very solid and will stand up to any overclocking youll want to do and the Cooler Master Hyper 212 will handle cooling for all but the most extreme overclocks. My old Hyper handled my 8150 up to 4.3 which is damn impressive. Seasonic power supply which is among the best builders on the market and a good solid case.
AMD FX 8350 @ 4.815 - 1.40V CnQ enabled
EVGA GTX 670 FTW @ 1070 (1239 boost)
Asus Sabertooth 990FX rev 1
Corsair Vengeance 1600MHz 8GB
Samsung 840 Evo 250GB SSD
Western Digital Blue 1TB x2
EVGA Supernova G2 750
HP 2509B @ 1920x1080
Corsair Carbide 500R
BlackWidow Ultimate & DeathAdder