I don't think you will find something that completely covers a 1 kanal house. Router range is affected by a number of factors including actual placement of the router and the number of walls the signal has to pass through. Even routers with extended range fall flat when the signal has to pass through a number of walls.
Positioning of the router is key. A central location is best, preferably the hallway, away from the walls.
My house is slightly larger than 1 kanal. I have a Dlink DIR-655 it works fine on on the ground floor but the signals barely reach the basement and top floor coverage is also poor.