Hi EvigOptimist and welcome. I want to start with a
for posting (1) the intended purpose of the PC and (2) your budget. I wish everyone seeking HW purchasing advice would follow your lead on that!
That's the good news. On the bad side and to your questions, note I am not a fan of overclocking. IMO, it is a marketing ploy only. Engineers design to specs, or to the limits of the raw materials and manufacturing techniques. They don't "design-in" overclocking. Marketing departments dummy-down the "published" specs. If you need more power, buy it.
That out of the way, there are technical and legal reasons to be concerned with overclocking, and alternative cooling too. Overclocking, by definition, increases the clock speeds "over" or beyond published specifications. This causes the affected devices to work harder and produce more heat. Added heat increases aging - that's just a fact with electronics.
This means to overclock properly, you must control heat removal from the case, not just the CPU - many motherboard mounted components are put under additional strain when overclocking - not just the CPU. This means for the next 5 or however many years you own this system, you MUST be EXTRA diligent at monitoring all system temps and at keeping the interior free of heat trapping dust. Sadly, as the PC ages, this becomes more important while users tend to lose discipline over time. And with liquid cooling solutions, maintenance discipline is especially critical as the system ages, as that is when hoses become brittle and crack and joints start to leak.
Note that engineers surround the CPU socket with heat producing regulator circuits. Why? To take advantage of the CPU's heat sink fan. Too many implementors of alternative cooling solutions fail to address the cooling needs of the rest of the motherboard, then wonder why their expensive motherboards failed prematurely.
On the legal side, see my comments about Intel and AMD warranties
here.
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For your hardware concerns, there are too many offerings that are constantly changing to be specific. I like Gigabyte, then ASUS motherboards. Since you already have a CPU in mind (and that's a nice one, for sure), then find a motherboard that supports it. Many sites like Newegg and Mwave have wizards that will match CPUs with compatible motherboards (and RAM). On that note, motherboard makers list CPUs and RAM they have tested be compatible with their boards, so be sure to check the websites for any board you are considering to ensure your RAM (and CPU) will work. Note you can download the manual too, and read up before it is delivered.
"Invest" in a good case. One that offers support for several large (120mm+) fan support and easy access. I will never buy a case again that does not include removable, washable air filters. I like Antec cases. And not fancy facades go out of style. And pretty lights do nothing for performance, consume some power, generate some heat, and do nothing for performance - worth repeating. A case should protect its contents from kicks and heat - otherwise sit quietly and discretely out the way - easily done with quality case fans.
One of, if not the most critical component is the power supply. Do not skimp on the budget. Get a good one from a quality maker. Select the PSU only after you have selected all your other components, then size and buy the PSU. I like Corsairs, Mushkin, and Antec PSUs.
Not on your list, a HD, DVD, keyboard, mouse or speakers.
Make sure your OS is 64-bit to take advantage of all your RAM. I agree for what you intend to do, and with that amount of RAM, the on-board graphics solution will probably be fine - they are much better on modern boards they they used to be. But before overclocking, I would buy a good graphics card if I wanted to significantly increase overall system performance, and especially graphics oriented content.