liberty has some AW rick already so you might get to see a decent amount there/ at the mayfair RO store by next month. hostem also stocks rick i believe, alongside BBS, yang li, guidi. definitely worth a trip to redchurch st.@snowmanxl
found a place on brick lane that sounded really good, can't remember exactly where?
harvey nichols also carries rick i think, as well as margiela etc. last time i was there they had a big section devoted to wooyoungmi which was really cool.
i'm not aware of anywhere that carries geller in london.
as mentioned, yohji flagship on conduit st is a must, and pretty much opposite you have issey miyake and then Y3.
if you want to see BBS/rick worn in the wild though you have to hang in out-of-the-way east london coffee shops