i have the same CPU with an asus board in an ML03 for my HTPC, currently using ARCTIC Apline M1 Passive cpu cooler, very cheap and just about fits inside my case, max temp i could get it to was 51c, there are no fans in the case, its 100% passive[the mesh just above the cpu will help a lot with that though]
cpu is very strong and the entire pc only pulls 21 watts when recording including HD homerun, extended idle, display switched off, so gpu will be off.
coupled with a GT 730 2gb, and 8gb of ram, it will play world of warcraft [very cpu heavy] at between 50 - 90 fps on 'high' settings @1080p.
only downside for me was only 2x sata connectors [i have an SSD boot, and 500gb 7200 record / scratch drive for pause] and i needed to add another HDD so i ended up buying a pciex1 - sata card to make that work, will probably pickup a nas later next year. can probably post some [i think now quite dated] pictures if you would like, its a very capable cpu and i am always surprised by how low the power draw is, and also how little it all cost me.
my parents next PC will be the same 5350, as it can [just about] handle youtube 60fps1080p, i dont have access to any 4k content or displays, so unable to comment on that.
i had the ML03 and i returned it and got the ML05 - the size is half that of the ml03 , obviously it requires a mini itx m/b
I havent had a chance of checking temps on the AMD HTPC as it was built today. I have no intake/exhaust fans on the cheap case i bought. Which s/w do you reccomend for AMD cpu temps ? Realtemp only supports intel - this is my first ever AMD CPU. Interesting point on the 1080p/60fps for youtube. i'll have to check that out tomorrow and see how it performs. I did try 1080p/30fps and it ran as expected, smooth.