Rolling Photo Backpack?

[skphoto]

I am looking for any suggestions or recommendations for a backpack for my photography adventure to Africa this summer, and hopefully many more to come. Preferably it should have the ability to roll because of my occasional hurting back. This is what I need to be able to fit :

15 inch laptop
Nikon d300
Nikkor 24-70mm f2.8
Nikkor 70-200mm f2.8
Nikkor 200-400 f4 (although this comes in a little bag itself, not sure if any backpacks could fit this lens)
Nikon 14-24mm f2.8
portable hard drive
various cords and cables

is this possible?!

[Bonish Photo]

Check out ThinkTank, they should have exactly what you're looking for and they're some of the best built packs onthe market. Owned and operated by a bunch of pro-shooters

ThinkTank Website