I like vent-a-hood for venting I also think more CFM like maybe 900 with 5 burners I am glad you are venting throgh the roof for sure . As for style I think get the you like with the proper CFM and it will work fine. I often use the same size hood as range but I just make sure the CFMs are higher. Most hoods have lighting I suggest to cange the bulbs to LEDs if not already there and remove the 2 pendants and just do pots there.

You definitely want a hood that’s at least six inches wider than your cooktop, so 42” for sure. To get input on this from those who know better, I suggest editing this question so that it posts in the HVAC forum instead of Design Dilemma. You can leave it posted to appliances and kitchens, though.

If you've got seating there I'd consider switching to a Bosch 800 induction cooktop. It'll need less cfm also because you don't get the waste heat production.

Hood requirements follow from the nature of cooking plumes. They rise at a velocity proportional to their pan temperature (plus combustion products with gas cooking), and they diverge (expand) as they rise. These characteristics determine hood entry aperture size for good capture and volumetric flow rate (CFM) for containment. With an island or peninsula, the hood has to overlap the cooking plumes on all four sides. This increases the aperture area and thereby the CFM required to ensure no plume spillage out of the hood.

Six inches larger than the range width and depth is reasonable, if it can be obtained. Volumetric flow rate of the order of 90 CFM per square foot of hood entry aperture area should be sufficient for gas cooking. Induction cooking may get away with less, but probably not for wok cooking or pan searing. These suggestions apply to typical residential hoods with low reservoir volume (volume below the baffles).

Island configurations are also more susceptible to cross drafts, so their potential strength and direction in any specific kitchen configuration should be considered when deciding on a hood size.

Thank you all so much for your replies! Any thoughts on the Zephyr brand - I had looked at ZLine and like their style as well.....