In reply to mrmoe17:
Lots of mentions of yorkshire/peak grit so far but not many people mentioning Lancs grit. Thorn Crag or Stony Edge are two brilliant moorland venues which most people love. Thorn would be a good stop off on the way up to the lakes.
As has been mentioned, summer is not the best time of year for grit bouldering, so moorland stuff is a better option than places like stanage and curbar, especially if you've been to those before.
However, rather than visiting a ton of sweaty gritstone/sandstone venues, you'd probably have great fun if you mixed up the rock types. Check out some limestone - Anston Stones maybe, or Trowbarrow/Woodwell. Check out one or two lancs quarries (Brownstones for easier stuff, Ousel's for 7's, Wilton 4 for highballs, Longridge for an endless overhang). Check out Pex Hill. Check out Bowderstone for steepness, Sampson Stones/Lad Stones for big days out, St Bees for seaside fun. You could have a great trip starting in the peak, moving up through the northwest and into the lakes.
And then there's Wales (north and south)...
And Ireland.
And Scotland.
10 days isn't long enough for all of the above!