For gaming, the graphics card is the real engine of gaming, more so than the cpu.
The 7850 is a fine card, no problem with that. At less than 1080P resolution, you should have no problems.
But, if your budget would permit a 7970 or a GTX670, that would be good.
I prefer graphics cards with a reference type direct exhaust double slot cooler.
They get the heat directly out of the case.
Other coolers do a good job in an open test bed of getting heat off of the gpu chip. But then they dump the heat back into the case where case cooling has th deal with it. That heats up both the gpu AND the cpu.
Ram is cheap. Since you will be using a 64 bit enabled app, like photoshop, consider going to 16gb. More ram speeds up processing by keeping more work in ram, avoiding hard drive i/o.
The Antec 620w HCG is a fine psu, in my opinion, better than the OCZ. It is sufficient to power even a GTX670.
If you are planning on cf later, you will need a stronger750w or stronger psu, and a more expensive motherboard.
More likely, a future upgrade will happen when there are stronger and cheaper graphics cards available. My upgrade plan would be to sell the current graphics card in favor of the next best thing, avoiding cf/sli issues.
If you start with a GTX670 now, I do not see that ever being necessary until you want triple monitor gaming.
The difference between 1866 and 1600 mhz Corsair Vengeance is only 7$ is that worth it or ?
@Geofelt what do you mean by i need a more expensive motherboard?
and when do you think future upgrades will be necessary?
Not worth it to me. YOU are the onlyone who can determine worth. 1866 ram is really 1600 ram that can be overclocked to 1866 with added voltage.
Also, the tall heat spreaders of the vengeance are actually harmful, in that they will impact many oem coolers.
Look for low profile ram.
In order to run cf/sli, you need a Full ATX motherboard with at least two separated pcie x16 slots, each capable of x8 speeds.
Other than the graphics cards, how many expansion slots do you really plan on using? For most of us, the answer is none.
A M-ATX motherboard is smaller and cheaper, with only 4 expansion slots. If your graphics power needs exceed something like a GTX690, then fine, buy a larger sli capable motherboard.
Personally, I like the smaller cases that a M-ATX motherboard will fit into.
As to when a future upgrade will be necessary, I think perhaps never. Or at least for a long while.
Game designers have little interest in producing games that take very expensive graphics cards to run. That would limit their market. If you will want to go to a 2560 x 1600 monitor, or triple monitor shooter type game, then perhaps sooner.
If you are a professional gamer, or have deep pockets, then the upgrade was needed yesterday, and will never be enough.
You want documented ram compatibility. If you should ever have a problem, you want supported ram.
Otherwise, you risk a finger pointing battle between the ram and motherboard support sites, claiming "not my problem".
One place to check is your motherboards web site.
Look for the ram QVL list. It lists all of the ram kits that have been tested with that particular motherboard.
Sometimes the QVL list is not updated after the motherboard is released.
For more current info, go to a ram vendor's web site and access their ram selection configurator.
Enter your motherboard, and you will get a list of compatible ram kits.
While today's motherboards are more tolerant of different ram, it makes sense to buy ram that is known to work and is supported.
A 8gb kit of 2 x 4gb will be good.
Look for DDR3 1600 with no or low heat spreaders.
Pretty much all DDR3 kits are compatible with most any motherboard even if its not on the list
True enough, but why take the chance?
Ram sometimes does have problems, and if neither the motherboard nor the ram vendor has it on their supported list, you get finger pointing and no action.
It only takes a few minutes to check.