Hi Steph - Golden Syrup actually isn't light corn syrup, but a popular product in the UK made from sugar cane. It is thicker and golden color (like honey) than light corn syrup. It can be found in the US, but at a price. The Foodsubs website gives many ideas for substitutions, and I think the one that calls for equal parts of light corn syrup and honey is close, especially in respect to the texture.

Hope that helps!