Most people use a pactor. The series 3 is the only one with a decent data rate, but costs as much as buying an inmarsat phone - which has a much better data rate and inbuilt modem and better connectivity and voice - but does cost more per minute.
I know which I plan to have, unless a much cheaper modem becomes available.
"Be wary of strong drink. It can make you shoot at tax collectors - and miss."
Robert A Heinlein