I guess my first question is, 40 kilos of what? I ask because the only thing "little" about me in my budget, and I'm decent shape- a 88 pound pack would slow me to a crawl and leave me dead and dieing after a few days. I can not advise too strongly to train up to this load, and even then keep in mind that a pack this big can turn a simple stumble into a serious joint injury due the shift in your center of gravity. Generally, when you see this much volume in a pack, most people are going with medium-to-low density items like sleeping bags, cold weather clothing and so forth as a large part of the volume.

For this much gear, I'd break it into three components- what is on your person, what is in your pack, and what is in your cart. And then I would look to see what just wasn't needed, and what could be substitued for with a lighter or more adaptable multipurpose item. The only time I can think of needing this much gear-weight would be if you were a paratrooper, were packing out part of an large game animal (and then I would NOT recommend something like the Norrona based on the pictures of it on their website) or were about to solo across the desert without a camel.

I know it doesn't answer your question, but the proposal raises questions in my mind and looking at what is going to go IN might help answer the question of what packs might suit your needs if we can lighten your load some.