I would certainly go with the larger hood. The rule in the kitchen design business is the hood should be larger than the cooking area. I try to make the hoods 12" longer than the cooking area so the smoke can be captured better. Since you have no cabinets on that wall, the hood will have a more difficult time removing smoke, as the lack of cabinets will allow more air movement between the cooking surface and the hood. If removing smoke is a priority, make sure you get a powerful fan system.

Ideally the hood should be 6" wider than the range. I think the recommendation above to go 12" wider than a 30" range is overkill.

"reasoning was something along the lines that with a bigger hood, you can install it a little taller (looks better) than the recommended distance between stove top and base of hood."

Either you misinterpreted what you read, or the person who said that is misinformed. I think what you are referring to is that a taller canopy-style hood will gather and contain, i.e., capture, the smoke and grease better than a more sleek-looking flat glass hood for example, or the smaller undercabinet hoods that are 3-6" tall. In addition, a taller hood has more of a wow factor and presence in a kitchen.

I would not equate a taller hood to being able to install the hood a greater distance above the range. Also if you install a hood too high above the range, the proportion can begin to look odd. Most of all, installing the hood too high above the range gives the smoke and grease more opportunity to escape. You wouldn't want to spend all that money on a hood and then curtail its efficiency by installing it too high. The ideal height is a 30-36" distance between the top of the cooktop and the bottom of the hood.

I didn't see any mention in the OP of exhaust duct size. Duct size is important. You could buy the best hood in the universe, but if the duct is not sized appropriately, the hood will have decreased efficiency and increased noise through no fault of its own. The most common required duct diameters are 8" and 10". The hood's specs will say which. For a 30" range, the 36" hood will most likely require an 8" diameter duct. Hoods that require a 10" duct typically are for 48" ranges or larger. Do NOT give in to your builder if he says "I am sure a 6" duct will be fine". That might be an easier installation for him, but you have to live with it.

I would go with a 36" rather than a 30". Theoretically you can go higher with a wider hood because vapors fan out and the wider the hood the larger the capture area. This is why ceiling mounted hoods are somewhere in the neighborhood of 54"-60" wide. They aren't for 48"-54" wide cooking surfaces, they are for standard cooking surfaces. The CFM of the exhaust is important, too. I think a smaller hood with a better draw is preferable to a wide hood that is all empty canopy and no guts.

But in general, yes you want to go about 3" wider than the cooktop, or more, rather than the same size as the cooktop.

Can you get a way with a smaller hood or have it farther from the stovetop if you are using an induction range? Realize you still need one for smoke/fumes but with less heat escape I thought you might be able to go smaller/higher.

99+% of American residences have no hood, a recirculating hood, or a vented hood the same width as the range/cooktop. Yeah going with the 36" hood is "better" but it is very rare to actually see it done.

Thank you so much!! You guys and gals are amazing:) I will definitely go with a 36". I just posted another thread under appliances to see if I can get feedback on specific contenders.

http://ths.gardenweb.com/discussions/4609888/m=23/please-help-me-decide-which-range-hood-to-buy

Thanks again:)