I'm getting ready for my first build and wanted you guys' advice on my build list: http://pcpartpicker.com/p/3MnlR. I went with the 850w power supply, because I'll probably be doing an SLI configuration in the future. Also, I'll be overclocking the CPU and GPU, so do I need to invest in more case fans? I'm doing an after-market heat sink already. I'm sure when I set up SLI I'll need more fans, but is it necessary for now?