If you want a basic aftermarket card and don't care about OV capability, let me first state as a preface that the ACX cooler is good - but it isn't the best option. I've used the ACX SC for several months now and while I like it, it's not as good as the Asus DC II or Gigabyte Windforce 3 cards. Both of those cards are better in terms of thermals and noise. Another consideration is the MSI Gamer card, it has been tested as the quietest kepler aftermarket cooler. Anyway, If you want something a bit better for the same price (compared to the EVGA SC ACX) I would go for either the Asus DC II or Windforce cards - I would have done that in retrospect, but the SC ACX was released before either of those cards were (at the time I bought my 780).
Don't get me wrong, all of these cards are good. But if you want to talk about noise and thermals on a "nitpicky" level, the ACX is just not as good as the DC II or the Windforce. All of these cards should boost well past 1000 out of the box even if they don't advertise such - the advertised boost is a bare minimum, it isn't uncommon to get real in game boost clocks 100mhz higher than advertised. I get nearly 1100 on mine out of box without overclocking - in fact, I haven't heard of an OC 780 card that *doesn't* boost well past 1000 out of box without overclocking at all.
OTOH, if you want to over-volt your only options are the 780 classified or 780 lightning. They're both about the same, although getting the overvolt utility for the classy is easier and more straight forward. With the lightning you have to email MSI and fill out some form apparently.
My rankings are something like this:
Without overvolting:
Asus DC II
Windforce 3
MSI Gamer
EVGA ACX
With over volting:
Classified or Lightning. The HOF gets some sick performance as well, but AFAIK does not have OV capability.