9 hours seems like way too long to leave a puppy home alone, in a crate or pen. Is there any way you could hire a dog walker to come during the middle of the day. You could find a student that might like the extra $. You could also consider doggy day care. I think if the dog gets used to going in the pen it will set him back. There was a girl in my puppy class with a 9 mo old boxer mix, she left it in a laundry room for 8+ hours a day. On the weekends when the dog had to go it would defecate in the laundry room even though she was home to take it out.