Political Science is way too dry. There are around 24 western political thinkers and they are complex, confusing and prosaic for any novice. There is more cramming in Pol. Science as compared to IR. Some of the recommended books like George H. Sabine's are extremely involved, the interesting ones like Ebenstein's are hardly to be found (unless you have access to some good library).

In short, IR is a much saner option, I believe.