You should keep the 24-105, 70-200, 580 flash, and 40d; then buy a 27" iMac with a 2tb drive and shoot like mad. I find most people have cheap $99 monitors to view their photos. An iMac is a great and easy to buy system, there are better monitors out there for lots of monies, but the iMac package is hard to beat.
Good idea - but I would suggest better AF will be needed for the sporting requirements. Not everyone wants to move from Windows to Mac.
Yes, I have an iMac already and I also have a MacBook Pro. Apple lover here:)
I did want to get a camera with a better AF that will compliment my new lens but I don't want to solely purchase based on sports as I also love portraits and candid shots of kids and the pups. I considered the Mark lll due to better IQ but hence the confusion. While who doesn't love the best of the best....I am trying to stay as grounded as possible and meet my current needs and current level of knowledge for photography.
With my limited knowledge and hours and hours of searching I think the 7D may make more sense but by all means I would not shut out the Mark lll if it would compliment my needs and be a better choice.