Touring centre of Chelsea, Cockney picks up posh types (5)
I believe the answer is:
earls
'posh types' is the definition.
'touring centre of chelsea cockney picks' is the wordplay.
'touring' means one lot of letters goes inside another (touring can mean going round).
'centre of' indicates the central letters.
'cockney picks' becomes 'ears' (I can't explain this - if you can you should give a lot more credence to this answer).
The middle of 'chelsea' is 'l'.
'l' inserted into 'ears' is 'EARLS'.
'up' acts as a link.
I am not very happy about this link. It may belong to another bit of the clue.
(Other definitions for earls that I've seen before include "London exhibition centre" , "Laser the British peers" , "members of the House of Lords" , "They're below marquess and above viscount" , "counts" .)