The 1st heatsinked you linked to is a 92mm heatsink, it really won't perform much better than the stock heatsink. The Thor is a unique design that works fairly well but it's fin design is a nightmare to keep clean.
I would go with the Prolimatech but it doesn't come with any fans. This Silverstone is my favorite, it pushes a lot of air and it comes with a fan controller if you find it to loud at full speed.
Newegg.com - SILVERSTONE FM121 120mm Case Fan
The Noctua NH-U12P is a slightly larger design (120mm vs. 92mm) than the Xigmatek and it's proven it's ability to dissipate a large amount of heat.