Low power PC upgrade needed - any help appreciated

[surreal]

Hi all,

I currently have an old low-power PC which I'm using as NAS and to stream/transcode using Kodi. It's an old AMD Athlon 5350(!) which has given sterling service but seems to be creaking a bit now.
I'm a bit out of the loop, so I'm looking for some suggestions to keep the upgrade price down and having looked at ************ I realise I have little idea where to start again.

I have a fairly large case and plenty of storage, I'm looking for mb + cpu + cooler + 16gb RAM, and maybe a replacement power supply but to be as low as possible as this is left on all the time. I think i have a 400w in there at the moment.
Won't be playing games so integrated graphics would be fine, but if it could be enough to drive 4k video sometime in the future that would be good.
If the board can have plenty of SATA ports that would be a bonus, but I am open to getting a card if needed.

Thanks in advance

Dave

 

[surreal]

See, this is why I can always trust this place... I don;t come here often any more but always guaranteed to get a detailed answer.

Thanks very much for this!