1st one has more fans, so it could probably overclock quite well. The second one is already overclocked but likely has much less headroom. I'd go for the first. If you don't like OCing, go for the second.
Personally I would grab the Asus since it is not a reference model and from the reviews seems to be one of the best 670s out right now.
The GTX670 runs cool. Fancy fans and coolers are mostly marketing for the GTX6xx cards.
I would pick the EVGA card because it has direct exhaust cooling that gets the gpu heat directly out the back of the case . It is also slightly faster with the factory overclock. 1006Mhz vs. 915Mhz
I would not count on OC for graphics cards. Vendors bin their chips, and the best go into factory overclocked cards so they can charge more. But, who knows, you might get lucky with either card.
If you're overclocking, the FTW has a +145% power limit, compared to others which only allow ~+125%. They also use the highest binned chips in the FTW editions. The Asus is their regular version, rather than the TOP version, so they use their lower binned chips. Binning may not translate into any noticable differences, but in theory the chips will run more efficiently and overclock better.
I guess I'll go with the EVGA one, because it is already OC'd, and I don't know much about overclocking GPUs.
Good Choice. Also be careful because most OC EVGA cards were recalled. Thought i don't think you will get a bad model since by now they should have worked out the kinks. I got the Reference clocked card and overclocked it my self. And Saved 20$ by overclocking it my self