The Ubiquiti Bullet linked here to their web site has the specs and details about the wifi booster. This is what Sea Trek used for their latest installation.
This is good for where ever there is cell phone coverage, although we carry two different provider devices, because we have come to realize that some cell phones coverage can vary depending where we are. Usually if we can't get service from one, the other will pick up. To complement this and increase our range, we use a cell phone booster, which can give us coverage up to 50 miles off shore. Take a look here for what a cell booster can do for you.
Finally, when we go to a different country, we go and buy their data sim and put it in our device, or buy their device depending how the country has set up their cellular data network. What do you use for internet?