1) Make sure the graphics card is silent as well, or connected to the water cooling. A PC is as noisy as its loudest component.

2) Generally speaking an i7 CPU is wasted in a gaming machine. The technological differences between an i5 and i7 are simply not used by games. The few percent a fucking expensive i7 is really faster than a cheap i5 2600k in games usually comes from a higher clock and some minor tweaks. So you could save a lot of money here with a performance impact you probably wouldn't even notice while gaming.
Of course things are different for some serious applications, when time is money.