Backpack advice please

Ok I have read pages and pages and pages of threads on backpacks and have got my self a short list, but I'd like your opinions please.

I'm going on a 5 day trip to Portugal to photograph a horse fair in November.

I'll definately be taking

Canon ID mk III
Canon 40D (can't risk not having a backup body or can I...?)
Canon16-35
Canon24-70
Canon70-200 2.8 IS
Canon 50 1.8
Canon EX 580 II

I like to take, but probably won't as it's rather heavy and I probably won't need it
Sigma 150-500

If I can get hold of a reasonably priced secondhand one
Canon 100 macro

And....
Powerbook pro 15"

Tripod
Monopod

Chargers

Mobile phone, wallet etc...


My short list is
Lowepro Computrekker or computrekker plus
Lowepro Compurover
Tamrac cyberpack 6
Kata DR-467

OK so what do you think????

Wow, no matter what you go with thats gonna be a big, heavy bag!

oh dear- what would you leave out then? The 40d?

lowepro nature trekker maybe

i would like to suggest a second backpack for half that stuff and also a second person to carry that backpack.

hehe man that's a lot of stuff. right now i use a northface surge with a dakine camera block. has a slot for the 15 powerbook and the dakine camera block fits inside the bag. there might be some space for the tripod since its has a lot of things outside to hook onto. still i doubt all that stuff might fit. i would test it for u if i have all that gear. send me your gear and i'll test it and send u back pics. hehe

That'll easily fit into a TT Airport Acceleration (sorry, I know not on your list but head and shoulders above the others imo).

Kind of depends on what application you need the bag for. If all you need it for is to cart stuff from here to there, any one will work. If it's also a bag to be worked out of, consider what you'll be using at any given time and if you really need something that big. Are you going there for fun or work?

My Acceleration usually serves as the carry-all and a location work out-of bag (i.e. bag is on the ground / table and I reach in and use whatever I need). For carrying stuff around and shooting, it gets too big and too heavy really, really quick. (That said, I do have a lot more stuff in mine than you would, but still, backpacks are pretty awkward to wear and shoot with.)

I'd recommend you take two bags: one large enough to safely transport all your gear and a second, smaller one to work out of / with. For this, I use a beltpack with pouches and only take what I need for each day's shooting.

Thanks for the advice guys- I know it's a lot, but I really think I need all the lenses.

Rafal_BC- I don't mind other suggestions at all- there are so many bags around,

It's work and I'm going to have to keep all of it with me the whole time as I'm not sure there'll be anywhere safe to leave it. I'll be able to leave the laptop at someone's house during the day but I'll need the rest with me and it'll have to be attached to me as I'll have to be able to move quickly.

Think Tank, hands down. It's huge and will stay comfy as much as possible on your back. It is as large as the Airport International almost and can be put on a wheely thing if needed.