I have the Canon 50mm f/1.8 II lens and I love it, so I'm sure the 50mm f/1.4 is a great lens (considering it has a distance scale and isn't made of plastic like the 1.8). It is the only lens I use due to financial constraints and it works great for skiing, you don't "need" any certain lenses you just have to be creative with how you shoot them.
If you are ever able to check out photos in people's profiles again, any images that are taken by me on this site are using the 50mm. I'd definately suggest buying it, you won't regret it, especially because it's relatively cheap and super fast.
What other lenses do you shoot with?