All calls at home anywhere in the world is on analog lines and you don’t have any problems right? Analog lines on a VoIP gateway produces about the same quality of a call just like the digital ones. Unless the PSTN (switch, lines, etc.) network is shaky, an analog gateway should be fine. In fact, many countries in the world analog is the only choice since a T-1 or E-1 is impossible to get.
Drop me a line if you have more questions or need help at firstname.lastname@example.org