Just to update those who are interested. I ended up using the Denon DRA-697CI. connected two pairs of the loudspeakers and they sound great! I then added a external amplifier to the zone 2 pre out to go to the garden area. Then added a volume control out there and another pair of the loudspeakers. They also sound great! I was very pleased and so was the customer! 

Thanks for all of your input. I always seem to learn something new every time I log in to this site!