We're on about Version No 99 of the packing list and we've moved from light-weight credit card touring to fully loaded expedition stuff, but I think we're finally sorted.  The original idea was that we would travel light, with just the bare essentials in rear panniers, and stay in hotels, B & Bs or hostels.  However, knowing Spain as we do, we have become increasingly worried that we might have problems finding such accommodation as and when we need it, although I suspect we would be OK in France.  We envisaged cycling a full day and finding ourselves in a some small place with nowhere to stay and no time to cycle to the next place.  So our solution is to carry the tent, sleeping bags and sleeping mats.  The obvious downside being the extra weight, but the upside being the certainty of somewhere to sleep and, of course, it will be cheaper.  Fortunately, we already have the camping equipment that we normally use when we are trekking.  However, we do now need front racks and panniers.  We can get all the stuff on the back racks, but we think the bikes will be 'back' heavy and unbalanced as they are, so I've just ordered racks and panniers over the internet.  We're nearly there - a good lesson for those new to bike touring - always give yourself several months to prepare.