Neither, if case is big enough, go for Noctua D14 or Phanteks, better performance than current choices. Otherwise, Thermaltake, as Seidon is loud and not excellent performer too.
I only have a budget case, Bitfenix Comrade, and have a very limited choices for CPU cooler for the budget. Thanks I guess I'll just have to go for the thermaltake as it has dual fan that I can use as an exhaust.
But if you have time, please check these links and suggest a better cpu cooler w/in the same price range of these two.