Clive, I guess you'll be considering a twin axle 'van, as most singles are not much over 20' overall towing length, with body lengths of about 17-18' max. In which case you'll need to be an accomplished reverser as twins are virtually impossible to turn by hand, or you'll need to invest in a motor mover of some sort. You'll also need a substantial towcar, as most 20'+ vans are 1500-1800 MTPLM, so a 4x4 is virtually essential or very large heavy saloon/estate with at least 180 BHP to cope with pushing 3-4 tonnes of 'van & car about. UK sites have no problem with twins, but some French sites won't admit them as they think you may be a traveller! Have great retirement!