I recently went on the same quest and ended up at Newark.
http://www.newark.com/w/c/connectors/usb-connectors-adapters/prl/results?st=panel+mount+usbI think this is the one I ended up getting:
http://www.newark.com/amphenol-ltw/ua-20pmfp-lc7001/sealed-usb-2-0-type-a-plug-ip67/dp/48W1020?st=panel%20mount%20usbthere is also a similar mirco usb port somewhere there too. Be aware that the pins are very close together and my be difficult to solder. I ended up etching a couple of small boards to give myself more room to work with.