I am looking to purchase either a Wide-Angle Lens or Converter for my Canon Vixia HF S100. I'm headed off to China soon and want to be able to capture the landscape and the cities in wide screen. Does anyone have suggestions for which lens/convertors are best? (or what the difference is between the two in the first place). Or how to determine their compatibility with my camera (58mm)?
I am a college student so my budget is limited, but I plan on going into filming for my career so it is important that the lens/convertor is not terrible. I don't really want to pay more than $120.

Chowhound
Comic Vine
GameFAQs
GameSpot
Giant Bomb
TechRepublic