Brivis HX series comes in internal & external config
http://www.gasstop.com.au/product/186/brivis-hx-23-i-xa
Has a 30 kw option extra $400 approx
Extra air option (bigger fan motor) extra $100
Needs to be run of a networker for full option (still 2 wire in wall)
http://www.gasstop.com.au/product/61/brivis-room-stat-networker