Hi Jules
First of all I think we might be able to help out on a book – we have two Clywd limestone Rockfax on the book shelves – good price to a good home!
Not been to your second suggested crag but been to Worlds End once – the grades felt nails but that could be more to do with me than the crag. Pinfold is another good option with a variety of grades and a few classics. Some of the quarries are good (e.g. Maeshafn) though popular routes are polished.