Changing kitchen sink - Must get contractor or just plumber?

Hi, 

Just got a resale HDB flat and need minor reno. Am a reno newbie so hoping some of the old-timers here can help me out a little. 

Just wondering... if I need to change a kitchen sink, I understand I will also need to remove/re-tile the counter top for that area (the previous owner put the sink in the service-balcony area so it's sort of separate from the rest of the cooking/work-top areas).

But do contractors do just that small amount of work? Or should I just get a plumber/tiler who can also do that + change toilet bowls + wash basin? Sorry if this sounds silly, just not sure if I should find individual vendors or get a contractor. 

Thank you in advance for your advice/help! 

cheers,

WH

Edited January 17, 20188 yr by whwh2018