US/Canada towing recommendation is 3300 lbs. In Europe, the S60 is rated for 1600 kg (3500 lbs), while the 2007 V70 and XC70 are rated for 1800 kg (3960 lbs) - even with the base 168 hp engine. (The XC90 is rated for 5000 lbs with the same light pressure turbo and 5-speed automatic, and it's a considerably heavier vehicle to begin with.) In short, 2000 lbs is nothing for your car to handle if the setup is undertaken with reasonable care.

As long as tongue weight (and cargo load in the car) does create a light front end, you should find the car to be an impressive tow vehicle. Volvo is the only vehicle manufacturer that I'm aware of that actually does instrumented stability testing while towing trailers.

Unfortunately, while Volvo builds superb tow cars, the Europeans don't understand weight distributing hitches (required for North American trailers with higher tongue weights), nor electric brakes. If you decide to upgrade to a heavier trailer, you would need a custom built receiver to handle the torsional forces imposed by a weight distributing hitch, and a brake controller and charge line would need to be connected directly to the battery.

Otherwise, a Class II hitch should be fine, whether from Volvo or from one of the aftermarket manufacturers. The best choice for trailer light wiring is the Volvo flat four pin harness. A bit expensive, but a simple plug-in to an existing connector, reliable, and not likely to do harm to the electrical system.

If you buy a car with an automatic transmission, an auxiliary transmission fluid cooler is advisable.

Enjoy!