Looking for a very quiet PSU for new build with PS07 case

[lego]

I'm building a very quiet/near silent PC that will be used by my family for web surfing, office work, occasional Photoshop, and as an htpc.

This is the setup:
CPU: i5 4590
Cooler: Scythe Kotetsu
MB: Not yet decided
Memory: G.Skill Ares 2x4GB 1600Mhz CL9-9-9
Case: SilverStone PS07 Black
HDD: WD Blue WD10EZEX 1TB
SDD: Sandisk Ultra Plus 64GB
GPU: No descrete GPU (Though, I might add one in the far future @$200 price level, but chances are not very high).

I'm planning to decrease the speed of the 2 SilverStone front fans to around 500rpm, and the cpu cooler to around 600rpm. It should hopefully be near silent. I'm looking for a PSU that won't add noise that will be audible over the undervolted cooler and 2 front fans. The PC will work most of the time at low load (I think up to 200W load). Ambient indoor temp in the summer may be as high as 30 degrees Celsius and A/C might not be used all the time.

I've been searching for quiet PSUs available in my country and these Seasonics are the best options I came up with within my budget:
G360 $80
S12G-450 $81
G-450 $105
G-550 $118
X-400FL OEM $124 (but only 3yrs warranty compared to 5yrs of the first 4 options).
(No KingWin here and Corsair RM450 is priced over my budget).

My default option would be the S12G-450 as it's powerful enough if discrete GPU is added in the future and it seems to have a good price/performance value. Would it be quiet enough (up to ~50% load) not to stand out over the undervolted front fans and cpu cooler?
Any chance the G360 or G-450 are more quiet?
Or the 360/450 wouldn't be quiet enough and I should go for the higher priced G-550 or X-400? If the X-400 arrives with the infamous coil whine, is it replaceable under the Seasonic warranty policy?

Thanks!

[Abula]

The X400 should be the quiestest as no fans, but it can have the coil/whine, idk if seasonic will let you rma because of it, i would think so, but idk better to contact them first.

I have done a couple of builds with Seasonic G550, one on a PS07, and while its not a super quiet psu, its very good imo, the fan always spins, and goes higher depending on the temperature, IIRC i never noitice it over the GPU, was a MSI GTX660, but there might be better alternatives.

[lego]

Thank you Abula.

Since I can get both the X400 and G550 for a similar price. Does the X400 have higher quality components inside and would be the better choice? I don't really need the extra wattage of the G550.

Is the 3 year warranty of the OEM X400 a significant disadvantage I should consider? Or it's the type of hardware that if it fails, it usually fails within the first couple of years.

[Abula]

Since I can get both the X400 and G550 for a similar price. Does the X400 have higher quality components inside and would be the better choice?

The X400 was my first fanless PSU, and has gotten good reviews in most places, even high end psu sites, the problem with it is the risk of getting one that has coil whine. From what i remember the modular cables are different, the X400 gold has like mesh a like cover on the cables, the G550 is more like corsairs where the cables aside from the none modular are just black plastic, something that Sesoanic has started to implement in their higher end paltinum, at least on my two SS-860XP2.

One thing to mention, is that G550 has two versions, or a new revision, Oklahoma wolf from jonnyguru did test both.
Reviews - Seasonic G Series 550W
Reviews - Seasonic G-550 F3 550W

I still think the X400 is a great PSU as long as you dont get any coil or whining.

Is the 3 year warranty of the OEM X400 a significant disadvantage I should consider? Or it's the type of hardware that if it fails, it usually fails within the first couple of years.

PSU components degrade over time, caps and mosfets wear down, so idk, persnally for me warranties are not a big deal as sending them from my country usually starts to get close to the price of PSU. But its up to you, some do buy products based on warranties alone.

[lego]

The G550 from the place I buy from, is the second version, it has the Haswell sticker.
About the X400, I will try to find out about the warranty policy regarding the coil whine.
Thanks again.

[lego]

I've got it down to 2 options since I don't need more than 400W:
S12G-450 $81
X-400FL OEM $124

The only question I have, if the computer is silent (no discrete GPU, fans & cooler are silent and non audible), would the S12G-450 be silent as well up to 40% (~180W) load , or would it be audible? If silent, it would be good enough. If not, then I"ll have a good reason for spending the extra $65 for the X400.

[quest_for_silence]

would the S12G-450 be silent as well up to 40% (~180W) load , or would it be audible?

As in any Seasonic platform, the fan is mainly temperature controlled: at an about 25°C, the minimum fan speed is around 600rpm up to your target power draw, but with just 10°C more (so at around 35°C) the controller should speed the fan up to around 750rpm at minimum and 1100-1200rpm around 180W.
So, definitely it's not truly silent: broadly speaking, it can be enough quiet providing that the case temperature is suitably low, but how much quiet is just your call.