Towing a caravan with a CVT gearbox will be a short life for the box. And this 2.4 Vs 3lt thing always comes up but really makes very little difference on the road. Parts seem easier to get then I thought it would be eBay has almost everything you will need. The 2.4 will be cheaper to service and maintain being a 4 cylinder. Have a good look under the car, almost all the Alphards I've seen are really clean, I wouldn't worry about the age thing