Just an update.
We decide to go for the Braemar TG420 warm air furnace. Has a 5 star energy rating.
We were able to get it fitted under the house with only a little bit of spare room.
Finished up with 9 outlets in the house and split into 2 zones.
The rep was very helpful and as we purchased and fitted prior to winter we got an extended warranty of 10 years and a free zone motor. Breamar were pushing this.
Now all we have to do is wait for this heatwave to clear and we can try it out.
Yay no more chopping wood or looking for kindling.
Blond not overly happy as there is no bum warmer supplied, my suggestion of setting up a porta potty over one of the ducts was met with a grim stare.