I'm also looking at getting a trolley in the new year. I've looked at this one as well, but for me I think once it's full it won't be coming out the back of the van as it'll be blooming heavy untill it's near empty and also refilling it when your out may be a pain.
For me one of the trolleys that take a 25l container would be best, as when the containers empty you could just pop another one in as you could have several filled and ready to go.