It depends on whether the "without too much of an issue" means towing stability or getting up steep hills at full speed.
All of those models have identical suspension and towing capacity, so apart from some brake capacity and low vs high profile tyre options, very much the same as far as stability.
The 2.5T is a fantastic engine and has plenty of room around for easy servicing. These models have the smallest brakes as standard on smaller rims, and you're going to drop some speed going uphill with 2 tonnes behind. That said, I don't think they're as bad as they sound for a small engine size.
The 3.2 is an oddball design - quite clever in its own right but you need to find a mechanic who understands what they're working on. The V8s are also easily wrecked by professional mechanics who don't know what they're dealing with. (That includes Volvo dealerships in my experience - bear in mind that the engine is actually a unique Yamaha engine and quite different to any other Volvo engine.
I have a V8, and it's magnificent for towing in my opinion. However my caravan is 1200kg all up and 2 tonnes won't be nearly as comfortable. Bear in mind that the tow capacity depends on the number of passengers on board:
So any more than 3 passengers and the tow capacity is only 1700kg.
Your other problem is that the V8s are quite rare, and for a decent low mile version even rarer and quite expensive. V8s are 2006 - 2010 only, and avoid the 2006 model if possible.
The 3.2 non turbo 6 is a fairly common engine especially in the later years, but it has some unique problems of their own. The engine is shared with the Landrover Freelander 2 but that's not necessarily saying it's a good thing. You have a better chance of finding a good one, but may have trouble finding someone who knows how to look after it for you.
Diesels are also reasonably common, but have swirl flap and typical modern turbodiesel issues - I've never bothered with them.