Good choices on gear. Going with the 1D X personally, but keeping the 7D because a 600/4 isn't in the cards (probably never, a 500/4 is my preference for portability, such as it is). 24-70 II is a great choice, I'd consider the TS-E 17mm over the 14 L.
Gitzo 5-series legs and a Wimberley II to hold the 600mm.
One comment about the friend's wedding. Good friend, or someone you hate? If the former, pay someone else to shoot it, or best case you aren't a wedding guest and you miss it and they miss out on your participation, worst case (which is pretty likely in the 'I've got pro gear so I'm off to shoot a wedding' scenario) is that good friend ends up hating you. Now, if and only if there will be an actual pro shooting it and you're just bringing your camera too, disregard the previous, but do introduce yourself to the pro, then stay out of his/her way...