Sorry forgot to address the used gear issue. I'd personally look for a new 5D at this point. That is a piece of gear that is coming down in price with the anticipation of the new version.
Used Canon lenses are a fine purchase to make, as they are very durable and really takes a lot for the AF or IS mechanism to go bad. However, the only problem is that they hold their value so well, you usually see most Canon professional lenses sell for within 10% or their original cost. In that regard, I usually just feel it's worth it to buy them brand new. That's just my opinion, and there are some good deals out there, but for the most part you won't save a ton of cash.
