Stock graphics cards are rarely quiet even at idle. If you are certain that you want gaming-level graphics, your best bet is probably to go for an aftermarket cooler. See for example the recent Build the Perfect Workstation
here at SPCR, where they use a Thermalright Shaman.
If the stock heatsink of the graphics card is decent, you could also just strip the casing and rig up a couple of 120mm fans
to get similar cooling with much less noise. In either case you are not likely to get quiet graphics without some sort of modification.
Cooling the overclocked CPU should be similar to cooling an overclocked i7-980X/990X, with a similar 130 W TDP.
Intel will sell their own all-in-one liquid cooler
for the Sandy Bridge E series. Unlike "real" (and expensive) water cooling, the all-in-one liquid coolers are generally inferior to air in cooling as well as noise. But they do take less room, if space is a concern.
I have no experience with "real" water cooling, but my understanding is that you can get better cooling than air, but rarely compete on noise.
For CPU cooling I would go with something like Archon, Silver Arrow
or HR-02 Macho
. Have a look at that last link, xbitlabs shows a diagram of temperature vs. noise
for a number of coolers on a 980X @4.3 GHz. That's the most relevant comparison you are likely to get before Sandy Bridge E is released.
(Note that the air cooler Archon beats the all-in-one-liquid Corsair H100 with a couple of degrees in cooling as well as ~20 dB in noise.)
That said, I don't think you can get a 130 W CPU with 30% overclock to be actually silent. Add the graphics card and the fans you need to dump >300 W of heat from the case (130 W CPU and 150 W graphics plus overclocking, disks, motherboard, PSU inefficiency etc.), and I think "less noisy" is pretty much the best you can do.
YMMV, this is just my take.