hi, just keep your eye on your nose weight. avondales are known for being nose heavy. we had a 2005 556/6 put it on the back of a 307sw and it almost bottomed the suspension out. the sales man at the time didnt tell us our car was only 65 nose weight.
Don't worry about noseweight, at 1250 mtplm you could go as low as 50kg,
I have towed a 1550kg boat with a 1500 kg BMW 5 series (G reg)and a Disco (L reg) and the BMW was by far the most stable and the BMW didnt use much more fuel despite being a 3.0petrol against the 2.5 diesel Disco
Hi Will, I have had a B5 shape passat (2004) and a B6 shape passat (2006). Both were/are extremely good car/s for towing my Swift which is about the same weight as your van. My earlier passat was the 4-motion and seemed to handle better though. Both cars were/are economical and because they are diesel had plenty of grunt. Hope this helps