First you need to mention where you are exactly. Internet service over satellite is usually sold through local providers. Furthermore, different satellites have different coverage areas.
Second, if you want high speed broadband, you will need a Ku/Ka band (small antennas) satellite terminal. The problem is that in South America, it is more common to use C band (big antennas) satellite terminals that are slower than Ku band since the spectral bandwidth is smaller and more expensive.
Third, the latency is basically the same for all Geostationary satellites and in practical terms is about 250ms from the transmission latency and 150ms for the latency of the entire transmission chain. As systems improve, this latency gets reduced but the transmission latency only depends on the relative position of the terminal to the satellite and the speed of light.
Forth, above 70C latitude it is not possible to provide Internet over satellite with geostationary orbit since there isn't enough visibility of the satellite on the horizon.