Priority Number one (and number twos)
Right, lets make this clear, if you haven't worked it out by now this is not going to be a luxury holiday!
Number one concern has to be comfort, including comfort breaks. Now transfers at main bus stations ought be OK, there ought be loos and also perhaps snack or coffee vendors to allow for a hasty lunch, although taking emergency rations each day might well be a good ploy. But roadside transfers. Publicans often are quite antagonistic to strangers wandering in off the streets just to use there facilities. Hopefully the story of trying to travel the length and breadth of the country for free might soften the hearts of some, but maybe it we just reinforce our image as freeloading ne'er-do-wells in the eyes of others. We shall see. Perhaps a bottle and a she-wee will also be essential travel kit!
Accommodation will be hotels. We could try and find friends, or friends of friends, or strangers we know via the internet to offer us a couch for the night but I suspect the rigours of several bone-shaking hours on Britain's finest buses each day is best rewarded with a (cheap) hotel bed.
We'll have to carry everything for the week in our back-packs and also probably need to wear our raincoats by default. It's going to be March, wet and cold are the natural state of affairs.
What else? Some foldable camping cushions for the derriere seem like a luxury we can't do without and a couple of micro-fibre clothes (in ziploc bags) to wipe condensation of the bus windows and try to allow us to make some sense of our route. And I suspect our Kindles will be used more than normal as buses meander through hedgerows hiding any scenery of interest or those 'little boxes, all the same' housing estates.
Oh, and I did mention brollies, didn't I?