I have seen this post on here and some other motoring forums all this internet stuff is new to me as you already know !!!
I would just like to point out before anybody wastes any of there hard to come by money !!
In my experience you dont really need chains in the UK but if your van requires new tyres now or autum then it is a really good idea to invest in winter tyres and change them in the spring . It is also a good idea if possible to source some spare wheels to make this job more managable .
In Europe and most defently alpine areas you will need chains but dont buy cheap ones as they will fall apart on your first ice climb !!!!! Invest in a good set and learn and understand how to fit them !! And dont run with them too slack !!! The new chains are a;lot more user friendly Hope I have been of some use for a change !!!