Your 16.49-4 even in OB trim will have an ATM of under 2T, so the Volvo will tow this comfortably and legally.
Make sure you get a later one with the 6speed, they didn't have trans problems.
I've got 3 kids and have owned over the years a Pajero, 2 Territory's and the Volvo XC90. All 3 were 7 seaters and for sheer practicality the Volvo wins, hands down. If nothing else, take a very good look at how you are going to be using it on a daily basis as well as travelling with it because I would strongly suggest that as you are going to need the 3rd row permanently up, a split seat is a far better option.
Those that don't split will rob you of a lot of storage and carrying space.
Food for thought, good luck
Yes a Disco is a Land Rover Discovery