Loocking for a backpack

[silicoid]

Hi

I'm looking for a backpack. I will do a one month trip to Australia. I want to store at Netbook my SLR (Canon EOS 450D with a Tamron 18-270), another lens, the red "The Pod", a flash and some other small stuff in it. The feature I look for is a removable camera bag. It should only take the SLR with the Lens attached.
I like to have a backpack so I have all the stuff with me, when I'm on a plane. But I don't want to take the whole backpack with me all the time, for instance when we have something to eat.
I checked the Thinktank Rotation 360 but it didn't have enough space for my Netbook.

I already have a Lowepro backpack which I use for my work notebook (and also bigger than a netbook), so I have my camera with me all the time. But when I'm on a business trip I don't want to drag it everywhere. That's another reason why I look for a solution that can carry all my stuff but also gives me the option to just carry my SLR.

Any recommendations?

[mridu]

any idea where can i purchase rotation 360 packback, it is out of stock everywhere