Both cards are very good, the Gigabyte Windforce however has a very nice, powerful cooler. I would take that one, if you have good case ventilation. The windforce cooler exhausts hot air into the case, and relies on your case fans to exhaust it out of the case. The MSI gtx670 power edition also uses that type of a cooler, but the one shown in the picture of the website you linked is a stock nvidia cooler which exhausts hot air directly out of the case. The MSI power edition, like the windforce x3 comes with a non-reference cooler, but it has the ability to overvolt, which will lead to better overclocks. However overall the gigabyte windforce card should meet all of your needs, and overall it has one of the best coolers.