We did the Wainwright Coast to Coast May 2006 St Bees to Robin Hood Bay (Irish Sea to North Sea). An epic walk.
We did it with luggage support and used the Contours Walking Holiday booking service: http://www.contours.co.uk/walking-holidays/coast-to-coast-walk.php
I was very satisfied with the service and selection of overnight accommodations ranging from small inn to B&Bs. Contours provided guide book, full set of Ordinance Survey maps, luggage service (which would transport walkers who wanted to bail on the day's walk).
We did the 14 walking day version with a layover day at Kirkby Stevens after 7 days of walking. Longest walk was 23 miles, flat but in the rain. Expect rain and wind but also expect sun and blue sky.
Trekking poles used and recommended. GPS got me back on route and unloss after following sheep trails on several occassions. Waterproof map case essential.
Given the luggage transport you only need to carry day gear. That said a couple of walkers were self-contained. We had extra meaning dry boots/ shoes in our baggage. I walked with extra pairs of dry socks in my pack. Even with rain pants and gaiters my socks got soaked on heavy rain days.
Be prepared to enjoy the company and friendship of others doing the walk and sharing a pint or three at the local pub comparing your daily experiences.