i. Intel 3570k maybe a small OC depending on noise
If you only intend a small OC then you do not need the k version. The k is only useful if you intend to do big overclocks due to it being fully unlocked. The normal 3570 will still overclock.
Would there be any material benefit in returning a 3570K that would make it easier to return as it (the whole computer is a gift work in progress. I would rather undervolt for noise than overclock.
ii. Mobo Asus Sabertooth x77
This will probably not be a good motherboard for noise. It has a built in fan and somewhat questionable cooling system when virtually all normal motherboards have been passively cooled for the last 8 years. In addition gaming motherboards like this tend to be poor for power efficiency. They generally get differentiated by showy features and gimmicks, I wouldn't buy one. Look at Asus' normal Z77 or H77 based boards if you want a quiet computer.
What board do you recommend, or should I just take the ASUS P8Z77 -V -Pro and be done with it (I pause over the lack of esata and the deluxe is quite a bit more). I also don't know what form factor to go for just want to game on two monitors unless the consensus is no more help if I keep the 2nd GPU.
Any reason for this larger size case other than being able to support the CP-850? It is now a deprecated PSU form factor so may cause problems moving forward. The P-280 or Fractal Design Define R4 would make more sense.
Again don't know what form factor to go for just want it to have an officially quiet case and remember the p150/p180. I figure if there's a better solution that's smaller than the 193 or p280 then I should go for it. I want advice on Mobo Case and PSU. Existing PSU is like 460 I think and that's just not enough for a modern machine I don't think.
I am going for SPCR approved case that will be big enough to fit two video cards and as minimal of a PSU as possible.