I can recommend MSI R9 280X (has twin frozr fan,10 mm), undervolt to 1137 mV.
They perform very stable at 720 kH/s with @ 75C at 65% fan speed.
I was actually experimenting today, with sacrificing hash power for lower noise, they perform well at 690 kH/s @ 78C at 50% fan speed.
50% fan speed is not making much noise.
But the ideal "wife approved" rig, would be to watercool the cards, however the rig will properly never reach ROI.
I use AX760 in my rig, it is general one of the most low noise PSU you can get.
I think I am miscommunicating something here. He doesn't care about the hashing really, just that it looks good. I have 3x xfx r9 280X cards for his rig... but he doesn't give a shit about the hashing. He cares that it looks good. He doesn't want the hashing, fine, I'll happily throw together a new rig and keep it...
So, to rephrase my original question:
What cheap ass cards can still hash at 300+?