Why use pine, it's just going to rot. 
Use PVC plastic lumber.
Some manufacturers have less expensive carriage house doors.
I have these, and they are good quality, without being crazy expensive: Haas 600 Residential Series Garage Doors
	
		
			
		
		
	
				
			Use PVC plastic lumber.
Some manufacturers have less expensive carriage house doors.
I have these, and they are good quality, without being crazy expensive: Haas 600 Residential Series Garage Doors