No problem
As with the above advice though, I would still recommend you save some money and go for the AX 650w, as it should be able to handle a GPU and any HDDs you add in the future.
Re the fans you could always try Sharkoon Silent Eagles or Gelid Silent 12's
You've got me thinking of changing from a 850W PSU to a 750W maybe. I need to check out some PSU calculators I think just to make sure.