Ideas please

Hi all, me and my long suffering wife are in the process of finishing the house over the next few months and will be putting it on the market. If all goes to plan we intend to live in our caravan for a few months from about September looking at various places in the uk to buy a new property and will tour and have a little holiday at the same time...... Heres the question. What is the cheapest way to stay on the sites? do we book a week at a time and stay on the CC sites or go for the affiliated sites....any ideas? the only stipulation is that we will have to have access to electric some of the time....thanks in advance Lee ( cash13 )