The reason I initially suggested these routers is that the are very small. Twice the thickness of an iPhone 4 but half the footprint. Also you can supply the routers power directly from the Arduino as these routers use USB power = 5V.
Also, here in the US the 702 ( not the 703) comes with an English interface. If you buy it through eBay and someone sends it from Hongkong then obviously the chances that you may have a Chinese interface on the 702 are higher.
Routers with external antennas tend to be bigger but really any router that has a bridge- like mode would work.