For rifles Huntingdon's Pak-It press was very good I am told. That used standard 7/8" dies.
For shot gun reloading I personally am not sure what actual advantage in weight saving you would gain as the case actually weighs very, very, little compared to the shot it carries and the space that that the cartridges take up is probably less than the space that the shot, plus the primers, plus the powder, plus the wads, and the tool would take up.
In fact I'd even say that for back pack use a 3" chamber 20 gauge would about take up the least room of all and yet still give adequate performance. In fact for most situations the now standard 70mm 20 gauge with one ounce of shot would surely do?
I don't see any saving gain - in weight or space - that taking a loading tool and components would give over carrying the cartridges. And indeed the cartridges could be stored in far more waterproof safe conditions than the components!
And if the tool breaks? Or a cartridge gets stuck inside whilst re-sizing? Oh dear!
For metallic cartridges where you only need bullet, primer, powder and you can get away with just neck-resizing then yes it makes sense. Maybe carrying twenty loaded rounds only but components for a further eighty. With say a Lyman 310 Tool and the small 310 Tool dies.
But the problem with shot gun cartridges is that the wads are bulky and the shot itself also bulky. I really can't see the advantages. Sorry.