Hello Alan,
I know that this is an old post now but could I ask you how you went on with your pellet stove? The reason being that we are wishing to replace our wood burning stove with an Artel pellet stove but are having trouble finding an installer - the sticking point is the flue system.
If you did go ahead I would be interested to know what flue size(s) you installer fitted. No worries if you didn't though!
Kind regards, Steve.