Usually the diameter of the hood matches the range and the cfms required are determined by a formula (there was a chart here with that info long ago -- anyone have it?) that calculates the length of the duct run, room size I believe and one or two other factors. Getting it right is not arbitrary or merely a matter of opinion. An overpowered hood sucks too much air out of the room and becomes inefficient. Going too wide risks ventilating your counters. A good quality, efficient hood with cfms appropriate to the range type will be optimal. Femmelady's kitchen shows that perfectly. She has a pro range with an indoor grill plus a 24" wok stove next to it. I think they went with a 900 or 1200 cfm VAH and a photo she posted showed it drawing out the grill smoke -- even installed extra high as her husband is tall. Here's a link. Surely there are enough hood styles that one can be found to look good with the cabinets. I'd be much more concerned with technical issues, a good brand and proper ventilation calculus, especially if you plan to go with a high-powered range and one of the monster gas ovens. Here is a link that might be useful: femmelady's hood install

I thought I had just the picture, but alas, it appears to be a 36" range with 42" hood too! But I don't think it would look too different if it was 6" narrower. The key is in the scale as was mentioned above by amck. If your kitchen is large and ornate, a 30" range will look out of scale no matter the range hood style. I have an idea book of wood hoods and this first picture is my favorite! It seems to fit in well. Here are a few more that are above 30" ranges, but I can't tell for sure what the hood size is. Looks to be only 30" on these last two. Ceiling height seems to be another piece of the puzzle of getting it to look right. Too short and the hood has to jut out too abruptly to reach the proper depth above your range. (If I remember right, you have nice high ceilings?!) Probably the only way to be sure you won't be surprised by the end product is to mock it up with cardboard shaped and colored like your cabinets will be. Then you can experiment with scale and slope, etc. (Can you tell I have researched this subject for exactly the same reason:))

The OP wrote: "So...I’d love the size of a larger range and a larger hood just for “style”..." Few want a larger hood for style; most resist having a larger hood even though it increases effectiveness at the cost of more required air flow rate and potentially a deliberate means of supplying make-up air. Cooking plumes expand as they rise, hence the hood capture aperture has to be larger than the area occupied by whatever pans might be used on the cooking surface. Otherwise, the effluent partially spreads into the kitchen allowing grease and moisture to settle on surfaces, and odor to spread and linger. A six-inch wider hood helps achieve this. A large enough front-to-back dimension is also needed. Assume the plumes expand at an angle of about 10 degrees from the vertical. The hot cooking plumes will have an upward velocity that depends on cooking surface temperatures and presence or not of gas combustion products. When these plumes (to the extent that they are captured by a large enough hood) reach the hood filter, they will bounce off due to conservation of momentum unless the air velocity induced at the filter by the hood blower is high enough. Commercial and residential practice suggest a value of 90 ft/min at the hood entry aperture (not the filter) is sufficient to retain the effluent and achieve containment. 90 ft/min is equivalent to 90 CFM per square foot of hood entry aperture. Use of induction cooking without any searing or wokking or hot frying may allow a lower value, but not below 60 ft/min. Hood blowers can only meet their specified zero pressure loss flow rate when hanging in free air. All other configurations have pressure loss (air flow resistance) as a function of flow rate, and thus when installed each blower flows less than its rated value. Buying a blower rated around 1.5 times that needed for containment (see above) should overcome the likely pressure losses, assuming there is a make-up air path suitable for the flow rate.

Hmmm. I wonder what design office would consider a last minute HVAC decision to be valid? In any case, one chooses a hood to adequately overlap the cooking zone and thus contain the cooking plumes, chooses a volumetric flow rate to ensure containment (90 CFM per square foot of hood entry aperture area*), chooses a blower assembly that can move that flow rate given the pressure losses from hood filters and duct and imperfect make-up air (or guesses by multiplying the flow rate calculated above by 1.5X), then determines the design of the make-up air system needed for the particular architecture, house leakage, and political environment. Besides reading my and others comments on this forum stretching back at least 10 years (or some subset thereof), the OP might consider providing more information. _____ *The flow rate one can get away with depends on the temperature the food is cooked at and the cooking heat source.