Spark plug wires

I am going to replace my sparkplug wires. I have stock wires right now. The dealer does not sell the wires assembled, and autoparts stores want $100 or more for a set. However, I found some wires on ebay which are only $45. They are 10.2 mm wires. Will larger diameter wires damage my car's electrical system? They claim to dramatically reduce resistance. Isn't that a bad thing? I am not quite sure. If anyone knows, let me know.