Ventahood has consistently gotten great reviews on this kitchen forum.

For a large gas range, you'll probably do better the stronger you can go with your vent. But do check your local building code: depending on the age and 'tightness' of your house, some areas require a makeup air system for residential vents over 600cfm, which can significantly add to the cost.

You might also try posting your question over on the appliances forum, where they know all the specifications, models & other details by heart. :-)

Here is a link that might be useful: Appliances forum