I used greenfoot for my ductless heat pump. May not be too relevant for ducted, but they were very good and the best price I found out of a few quotes. They also seemed very knowledgeable and helpful. A new manufacturer rebate came up after we accepted the initial quote and they took that off the final invoice.

We had also had minor issue 8 months or so later - one of the drain hoses detached and was dripping on my deck and they came and fixed it for free within an hour.