Architect stalks one of those trendy types who could do with a shave (8,7)
I believe the answer is:
designer stubble
'those trendy types who could do with a shave' is the definition.
I don't know anything about this answer so I cannot judge whether this works.
'architect stalks one' is the wordplay.
'architect' becomes 'designer' ('designer' can be a synonym of 'architect').
'stalks one' becomes 'stubble' (I can't justify this - if you can you should believe this answer much more).
'designer'+'stubble'='DESIGNER STUBBLE'
'of' is the link.
Can you help me to learn more?
(Other definitions for designer stubble that I've seen before include "kind of personal appearance" , "Fashionable unshaven look" , "shave this?" .)