What year is your Hilux? Is it an Auto or manual? My Dad had a Hilux at one stage and I borrowed his Hilux and caravan and took the family from Melbourne to Canberra and back. If you are not familiar with that stretch of road, there are some decent hills. The Hilux he had was a 4 speed auto (2010 I think) and the van would have weighed close to 2500kg. It did the job but I would say that comparing it to my Isuzu MUX, the MUX seems to do it a bit easier. I put it down to the MUX having a 5 speed auto. Having that extra gear means the vehicle does not have to work quite as hard up the hills. My mate has recently bought a brand new Hilux manual. He has put in a chip and a larger exhaust (resulting in needing a heavier duty clutch) giving it more grunt, he has a van that would weigh around 2300kg and he is extremely happy with how it tows.
I would say that yes it would do the job but there are others that could do it and not work the engine as hard. If you find you are not happy it would be cheaper to add a chip.
Enjoy the new van!