Hi Rob, sounds like you should have a fun trip and really enjoy yourself. I haven't gone on one of those, but I do a lot of urban shooting and like to capture new places when I visit.
I also have a 5D and some of the gear in your sig. My cards are only 2GB though, but I buy them on sale and they get me through my wedding work shooting RAW at the rate of about 150 images per card. For the trip though I'd buy 4 or 8GB cards - they are very small, lightweight and take up little room. I don't own a storage unit, and would not be inclined to get one. To me that's just more gear to get in the way, and to possibly fail.
Now I will take a different approach here: I don't think you need to take everything on your list?
You will likely take 85%+ of your shots with the 24-105L. That is a fantastic walkaround lens and I've done most of my urban and wedding work with it. Take that. I don't see any point in taking the 50 1.8. There's an overlap there and it gains you little.
The 17-40 is an excellent light weight lens and will give you great UWA shots, and back up half of the 24-105 in the event of failure which I doubt. But at the same time it's not critical to take it unless you don't mind the extra gear. The 1.4 extender is good and so is the 135.
I'm NOT a fan of spray and pray, especially since you can always check your work. Remember, your brain and eyes are the most critical parts of your kit. Look, think, compose, shoot. Don't clutter your cards with stuff you will just delete later. You want to concentrate on the good stuff.
That being said, you can easily shoot 200-300 images/day. Do the math and figure out which cards you want to buy or already have. Have fun
. - Stu