My quiet PC has exactly one missing component: a quiet FlexATX psu with a size similar to 80x65x170mm. I have been searching for such a beast for several months now but keep coming up short. I run into one of two cases:
1. I can find reviews showing how good the psu is but can't find any actual units for sale anywhere
or
2. I can find actual units for sale, but no reviews as to whether or not they really are quiet

For example, I see that the Seasonic SS-120NS and SS-105NS are both the perfect size and are very highly regarded. However, as the Seasonic US rep told me, they do not stock those models in the US so there is no place I could get them.

On the flip side, a few sites have Fortron models like the FSP145-60PA which will fit (with a little effort) but I have to find even ONE review of them and thus have no idea if they really are quiet or not.

So I'm asking for help. Are there any FlexATX PSUs available anywhere that I could buy them that are very very quiet yet will fit in space 80x65x175mm?

Thank you!

I haven't tried any Flex-ATX, but I did try a 180W Fortron microATX. The coil was buzzing, the fan was blowing the wrong way (from the backside and into the case), it was only Passive PFC, and the heatsinks was small. Then I got a Seasonic SS-200SFD, and everything was good.

Can't say if the same is true for the Flex-ATX, but I would be sceptic.

I was afraid of that. I wonder if I'll have to go the route of either getting a bigger case or getting an ATX psu and using it as an "external" one of sorts.

The fans on Flex-ATX PSU's come in 2 varieties; 40mm fans on the back, or 80mm fans on the bottom. (Just like micro-ATX's) You may want to shop around for one that has an 80mm on the bottom and then switch the fan with a queiter one.

That may be a relatively simple way of making it quieter.

Have a look at the way I used the Seasonic MicroATX PSU in the Breadbox PC. The whole thing is very small & the PSU is very very quiet. That whole PC can barely be heard sitting on the desk next to the monitor.

The PSUs i mentioned use 80mm fans. Part of the problem with the Fortron was that there wasn't space for a 25 mm thick fan, but that was easily solved by mounting the fan on the outside. The real problem was the coil buzzing. Don't know if there is enough space in the Seasonic for a 25 mm thick fan as I haven't seen any reason to open it yet (same model MikeC use in his breadbox). The Seasonic has a slight vibration when it speeds up, so I might need to put something between the case and the PSU, but I need to experiment some more. The PSU is mounted about 10 cm inside the case (next to the CPU) with walls to the backside to prevent the air from returning into the case, but there is some work left on this.

Very nice! Unfortunately for me, I measured my case every which direction and there is no way I could fit any MicroATX PSU in it.

Hmm.. do Seasonic MicroATX PSUs come with long cables? I remember an Enermax PSU I had some time back that had cables around 2 ft long.

Your suggestion of a external PSU maybe necessary if you can't find one. Hey you could save money too, you can get a generic PSU that does not have coil buzz and mount a panaflo fan outside of the PSU at very low voltages. Since it is outside of the case I bet you could get away with 5 volts, that would be very quiet indeed.