The immediate answer to your question is yes the product will be sufficient and yes we would recommend the Heater option.
However, we would like to help you choose the correct product for your requirement and I am inclined to question why the flat suffers from condensation and is there something else that can be done to relieve the problem.
So, if you have time, could you answer the following?
Do you live there or is it rented out?
Ground, 1st - 2nd floor etc does it have a balcony?
What ventilation do you currently have in the kitchen and bathroom and how do they work (ie don't have any mechanical ventilation, fans manually operated, light activated, humidistat control etc)
Is the problem throughout the dwelling or appearing in a particular room?
Has condensation always been a problem or has it appeared recently?
Should you want clarification on why these answers may help I can be contacted on 07956 818138