For future reference if anyone needs a pad in the Lakes, Alpkit Ambleside could not have been more friendly and helpful.
They have 2 pads, a medium size one (Mujo) and a big thick one (Origin I think), £10 to hire for a day. I took the big one and it was great for thrashing around on the Langdale Boulders, fell off the top a few times.
Would recommend the pad and the store (and the Langdale Boulders!)