looking for advice on a woodburner

please help, we are currently looking at having a wood burning stove installed. However there is such a huge choice of stoves would love to hear some feedback from others:

current fav is a olymberyl make- anyone heard of these?
also open to suggestions:
want around a 6 kw output, and to spend up to about £600 on the fire itself.
been told we need a flue size of 5"
thanks in advance!!!