the coast to coast i know is the whitehaven to my town sunderland.
i ride the last 3rd every year for charity. i aint done the whole thing but freinds of mine who have say its more hilly at the start and last 3rd is the easiest. 1 freind done the c2c in one run.
i will be doing it over 2 days riding. not sure of the other c2c but im sure there is a more off road version of it that was featured in the MBR mag a few months ago and they said it was super solid.