presuming your washer is similar to this
http://jet-wash-direct.co.uk/pressurewashers/task-pw200ph.html with similar stats then i'm not sure if it will provide adequate power to use a fsc to max effect, my machine is a bit more powerful and is suitable for one (somebody else may advise better).
Saying that its not all about bar/psi , your water flow rate is just or even more important and at 900ltr per hour or 15ltr per min that is suitable for use with a fsc ( flat surface cleaner / rotary washer ).
It may be worth asking other members about a turbo nozzle which a lot of people prefer to using a f.s.c., personally the lance I use has a good jet on it and is often more or not used more than a f.s.c. on large areas.
A f.s.c. will not clean the joints out of block paving very well and will require another going over with the lance this uses more time and makes a lot more mess.
Search these message boards and you will find these questions have been answered many times and you can decide what is best for you.