If it was a reliable PSU then I would have suggested 4670.
But it doesn't seems so.
So I also recommend you to get a better PSU for the Gfx card upgrade.
Also mention your Budget.
Any card below 4650 GDDR3 is strongly not recommended cuz they don't provide good performance.
"also random question but are GPU fans annoying? so heat sink vs fan? "
No.Fans are not annoying.
In most cases they remain silent throughout their lives.
Also it gives better cooling which ensures better lifespan and good chances of Overclocking.
Fanless cards are bit more expensive.