Has anyone found a tough wheeled backpack for pulling 12 kgs of gear over rough ground?

Has anyone in Europe tried any of the bags listed here:

http://www.ebags.co.uk/victorinox_swiss_army/trek_pack_plus_3_0_61cm_wheeled_backpack_with_docking_daypack/product_detail/index.cfm?modelid=83928

I've bought this bag http://www.amazon.com/ZUCA-Frame-Inserts-Travel-Cover/dp/B0016FVGYW

The interior has not been made for my camera, i.e it does not have the protection. However, I intend to have the inside finish with a foam especially made for my XL2 and it accessories. The advantages that I've founds with this bag are :
1 - You can carry this bag (the PRO one only) inside the plane (Length + width + height = 42" Total, within FAA requirement);
2 - It has wheels (very solid);
3 - The frame is very solid (can support up to 300 pounds); and
4 - You can sit on it which I intend to when filming;

That's the right size wheeliebag and seems tough enough for the wild, Daniel, thank you.
However, it weighs 13 pounds (5.45 kgs) which is half the weight some airlines allow in a carry-on bag. My 12 kgs of gear would have to be split between 2 of these bags.

Any similar sized suggestions with backpack straps, please?

I use the LowePro Nature Trekker if I need a tough, comfortable and waterproof highly-protective backpack to trek over long distances, and it is also OK as a carry-on for flights.

It is easy to fit the XL2 plus extra lenses etc in the LowePro pack if you split the body, finder and lenses seperately, and I'm aslso able to fit my Pro stills F5 camera bodies or long telephoto lenses such as the 300mm and 600mm Nikkors.

However, when on location filming (when I often don't need to trek long distances over tough terrain), I use either my Portabrace or Kata bag that allows me easy access to the complete XL2 with viewfinder and 20X lens attached.

I use the LowePro Nature Trekker if I need a tough, comfortable and waterproof highly-protective backpack to trek over long distances, and it is also OK as a carry-on for flights.

It is easy to fit the XL2 plus extra lenses etc in the LowePro pack if you split the body, finder and lenses seperately, and I'm also able to fit my Pro stills F5 camera bodies or long telephoto lenses such as the 300mm and 600mm Nikkors.

However, when on location filming (when I often don't need to trek long distances over tough terrain), I use either my Portabrace or Kata bag that allows me easy access to the complete XL2 with viewfinder and 20X lens attached (plus 3x lens and radio mics, etc inside).

I use the LowePro Nature Trekker if I need a tough, comfortable and waterproof highly-protective backpack to trek over long distances, and it is also OK as a carry-on for flights.

It is easy to fit the XL2 plus extra lenses etc in the LowePro pack if you split the body, finder and lenses seperately, and I'm also able to fit my Pro stills F5 camera bodies or long telephoto lenses such as the 300mm and 600mm Nikkors.

However, when on location filming (when I often don't need to trek long distances over tough terrain), I use either my Portabrace or Kata bag that allows me easy access to the complete XL2 with viewfinder and 20X lens attached.

This sounds very useful Tony, thank you. I'll be checking out the Nature Trekker.

In the meantime you seem to imply that the Portabrace or Kata bag may not be OK as a carry-on for flights. If that's true, which models of these are you using?

Both the Kata and Portabrace are OK to use as carry-on baggage.

Portabrace:
http://www.portabrace.com/category_50_54

Kata:
http://www.kata-bags.com/Item.asp?pid=3&perentId=1&ProdLine=1

LowePro:
http://products.lowepro.com/product/Nature-Trekker-AW-II,1971,14.htm

I used to use the CCC-1 Kata bag (now discontinued in the Kata lineup), but this past year I have been using the Portabrace Traveller bag for the XL2 a lot more for my overseas trips.

If you must have wheels on your bag, then LowePro also produce very good "roll-on" camera packs for use on flights.