First-past-the-post vs Proportional Representation

With the US election coming up this November, we were interested to see how the election results and the distribution of members in the lower house of the parliament and the Government of Austria could look like if we used the first-past-the-post electoral system. This election system is used by many English-speaking countries. (The system of Nebraska and Main for the United States Electoral College are ignored.) We wanted to see if the structure of the results would be similar to the results of the USA.