SMD vs THR Transistor for Relay
What do you think about used SMD instead of THR?
  


I think you should use whatever fits your budget, BOM, capabilities, and requirements.


  
  Will transistor be able to dissipate power?
  


Your application is not high-power in the first place, so any TO-220 or TO-263 will more than suffice, and possibly be overkill.


  
  MCU, would it deliver enough current to activate the base?
  


The 20mA should suffice for a transistor with a sufficiently high hfe.


  
  Do you have any recommendations?
  


You forgot the last specification: coil current. You should use whatever transistor has a high enough gain and current handling for the coil.