Suitable sucker? (7,5)

I believe the answer is:

tailors dummy

I'm a little stuck... Click here to teach me more about this clue!

'suitable sucker?' is the definition.
I know nothing about this answer so I can't tell whether this works.

'suitable sucker?' is the wordplay.
'suitable' becomes 'tailors' (I can't justify this - if you can you should believe this answer much more).
'sucker?' becomes 'dummy'.
'tailors'+'dummy'='TAILORS DUMMY'

Can you help me to learn more?

(Other definitions for tailors dummy that I've seen before include "Mannequin" , "one beautifully dressed" .)

I've seen this clue in The Globe and Mail.

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