I need help deciding on the rest of my system

[Peebugger]

What I have:
2 Gigabyte geforce gtx 660 (sli)
2 TB Seagate Hybrid Drive
16 GB G.SKILL Ripjaws (4 x 4GB) DDR3 1600

I'm open to just about anything but I am really looking into the Intel i5 3570k processor and I really want to get an NXZT Phantom if I can. I need help deciding on everything else because this is my first build and I REALLY don't want to screw it up. I really want to overclock my CPU because I have done a GPU before, but never a CPU. All input is appreciated, thank you.

 

[iceclock]

what parts u need and ur budget

 

[Peebugger]

what parts u need and ur budget

Currently I have what is listed up top and all the peripherals that I need. Astro a50s, corsair k95, and an ASUS VG248QE. I do have a really nice system now, I just kind of wanted to build my own custom PC and pass down my current PC to my little brother because I know he really wants one. I currently have an Alienware aurora with an i7 930 (which I am unable to OC because of Alienware's bios). It has a liquid cooling system with one Gigabyte geforce gtx 660 (I just ordered a second because it was super cheap and came with two free games but if I do give my brother my PC I'm just going to get like a 650 ti and throw it in for him). I have the 16 GB G.SKILL Ripjaws in the system currently but I'm going to take that out and throw the original 6 GB back in. The 2 TB Seagate Hybrid Drive is also on its way and my current system has a 1 TB hard drive in it. It also has an 850 watt power supply and the motherboard is just some stupid alienware with only 2 PCI expansions slots (another big reason why I want to upgrade). I really don't have a limit on how much I will spend because if I need to I can just work some extra hours and save up until I have enough but it would be nice to finish off my system in the $500-700 range. Also, some people said I should just wait until next year when the new Broadwell CPUs come out. I guess if I decide to keep my system I could always just build my little brother a system with the extra components I have. Any opinions?