I have seen Decleor in Superdrug but not the whole range, just a few items, never seen it in any Boots stores.
I have seen some Nails Inc, LD and OPI in Boots but not a huge range. Frasers here have a Nails Inc bar, Decleor counter, Elemis counter and a Bare Escentuals counter, neither of those brands are in Debenhams in the city centre but Debenhams in Silverburn have Bare Escentuals.
John Lewis has a small amount of OPI and Nails Inc but no Decleor or Elemis. They have recently started stocking quite a large amount of Ojon but their selection of Philosophy items has got a bit smaller.