I need some advices 1200Euro build+monitor

I want to build a new system but i cannot decide what to buy.I have some pinned components and some missing one's (i haven't bought anything)
Till now i have decided to buy these:

M4A79XTD EVO
AMD Phenom II x4 955 BE
Sapphire HD4890 Vapor-X 1GB
WD 1tb 32mb Caviar Black

Now i need to buy some ram but i don't know what king i want them to be good and reliable and to stand a overclock.I'd like 4gb at 1600mhz or 1333mhz maybe 6 gb if they are cheap enough.I am a big gta fan so i would like to play GTA IV on a Samsung T240HD on its native resolution.I know i can play on that resolution but i want to max it,well not really max,everything but the draw distance.Maybe the draw distance at 40.I want to know that if somebody who has or had this kind of monitor can tell me if i can play the game at 1680x1050 and the game looking like 1920x1200 or almost.I don't mean the edges i mean the clarity.If it looks about the same it's fine.I almost forgot to mention about the PSU.I though that this one is good and it can hold it Chieftec Super CFT-750-14CS 750W.I want this pc to be silent and when i'm not in games to consume less energy and be as green as possible.I hope that it will fit in a NZXT Apollo.I'd like to keep the price as low as possible and to have some backup parts if the vendor from where i am purchasing doesn't have them.A backup for RAM and PSU i mean.
I don't want to order anything i will buy them from a local vendor.
i will use it to play games and lots of games,I don't prefere any brand or something.

Your choice of power supply and case are also fine if you want to stick with them.

Both will be fine.

http://ati.amd.com/products/radeon [...] -4890.html

Where did you see dual in the OP?

I don't see that anywhere, and I'm pretty sure that wherever you did get it from, it's just saying that the PSU has those connectors in case someone is considering crossfiring a couple of lower cards, not that anyone is planning to put two 4890s on it.

Oh, well at least that's where you got it. It might apply if the OP wanted crossfired 4890s; as he doesn't, it's irrelevant at best (though interesting).