Its a cool build, i was thinking of doubling up on the HDD tray in a fractal too but in the end only went with 8 drives.
I think you should consider using ECC memory for a file-server as well as a more robust raid system such as ZFS.
ZFS has multiple advantages over hardware raid, most importantly the config of the raid is not stored on the controller there is a copy on each drive so if the card where to fail you would potentially lose all of your data ( you may be able to recover it but its not a guarantee ). With ZFS you can plug them drives into anything and as long as it has as new a version of ZFS or higher you can get your data back , hell you could plug them all in via USB if you where desperate.
ZFS also has much better error checking ( as in it has error checking) than hardware raid, normal raid systems are quite happy to serve up a corrupt file even if there is a working copy somewhere else on the array.
ZFS also has de-duplication built in, if the files have the same checksum and the metadata is the same it will only store one copy of the file.
And most importantly snapshots! ZFS can take a snapshot of itself , this is not a full copy of the data (ZFS is more intelligent than that ) it will record any changes you make to the data ( so the snapshot will slowly take more space over time). SO you can do things like upgrade the whole OS , if it goes wrong hey you have a snapshot you can boot into and get back up and running in the time it takes you to reboot, you then just delete the newer set and you are good to go, open indiana does this with any update of the system no user interaction required

.
ZFS also has advanced cache both read a write cache can be set up on fast media ( such as PCI-e SSD) to give you a massive boost in read and write performance. ZFS also chases to any free memory you have further improving speed ( this is part of why you should be using ECC ram for data integrity) the only slight issue is to take full advantage of the memory chasing its recommended 1GB per TB of storage.
There is RaidZ1 RAIDz2 and RaidZ3 ( single double and triple parity) recovering for a failed drive is also MUCH faster due to the way ZFS stripes the data ( i am not an expert so i don't fully understand how this works but it is significantly faster ) and you can also keep using the array ( with degraded performance) when the drive is being replaced.
Anyway as for the PSU i would go for the fully silent one myself

.
Oh and most SAS to SATA cables are universal so you can get replacements in any colour you want

.