Bag help

[happysnappy]

At the moment I use a Tamrac Expedition 5 that I've had for some years & it's been faultless. Only problem now is it's not big enough.
I've started looking at the Expedition 7&8 & the LowePro Trekker series, what are people thoughts on each?
The kit that needs to fit is:
EOS 40D with grip, 20D with grip, 70-200 f2.8 with hood, 24-70 f2.8 with hood, 35-135 old usm, 18-55 kit lens, speedlite & various batteries, cards, filters etc.
I prefer backpack type bags as I have to walk a fair amount of the time.
Any suggestions welcome as I don't want to buy something & find it's not upto the job.

 

[Ric Type R]

If you are satisfied with the 5 Get the 7 or 8, I have the 7x it holds more than I can carry.

 

[PsiFox]

I have the Expedition 8 with everything in my sig/forum camera bag and more including batteries, chargers, filters etc.

I find it incredibly comfortable for extended periods (over 10 hours on occasion)