Google would be a good place to start, all right. But talk also to your cell phone supplier. I KNOW some cell phones can accept an add-on modem and connector so that a portable PC can use the cell phone / modem combination to communicate via a form of dial-up conection. And I am also sure that some can do a similar trick with stand-alone FAX machines. These were in use before wireless network systems. So, depending on whether you plan to send and receive FAXes through a FAX machine or a PC, you should be able to find the equipment. Not at all sure about costs, though!
By the way, as a trucker are you familiar with cell phone booster amplifiers? With or without a hands-free system, they can extend the range of good signal for a cell phone by quite a bit - 30 to 50 miles more, in some cases. So if you travel through marginal signal areas often, these systems may give you more reliable coverage instead of dead zones. I have one in my car and it works well.