I think a 900 cfm blower should be sufficient for the home cook. I think the 1200 + cfm hoods are more suited for a professional kitchen.
I have a 500 cfm telescopic downdraft (my 36 inch cooktop is in my island) and I chose not to go with an over the ceiling hood. I like an unobstructed kitchen and the telescopic disappears when I dont need it. Also the downdraft (regardless of what I had heard about it) works extremely well for me and my type of cooking.
My aunt has one of the super professional 1000+ cfm overhead hoods and it is extremely noisy. Most times she never cranks it up anything more than the lowest setting. At the highest setting you would have to almost scream to continue your conversation
Just keep one thing in mind that if you are going for a fancy glass type hood the cleaning sometimes can be a pain and this is from my neighbour who has a snazzy looking one especially if you cook a lot but it does not sound like that you do that sort of heavy duty cooking so you should be alright.