High Quality Skype Via Mobile Internet

I'm looking at some houses in the Chiang Mai region but need to make/receive 10-20 calls a day via Skype/Vonage with the U.S. Reliability and quality are important as these are all business calls. Ideally, some type of home router would be ideal so that I can plug in my Vonage device by ethernet cable but a USB modem that provides a broadband connection to my laptop would also be an acceptable alternative.

I was wondering what the best mobile Internet provider/set-up I can sign up for to ensure coverage, reliability, and quality?

For example, one house I am looking at is in the hills of Mae Rim (Google maps 18.8967, 98.9105).

Apparently, there's no land-line Internet going to that house but some type of USB modem seems to work. I'm just wondering what set-up would allow for the best guarantee of reliability for voice over IP calls to the US.

Thank you. Would appreciate your thoughts and expertise.

Edited August 16, 201015 yr by midnighttiger