I think a big fat hood will look better with the layout anyway. Those chimney ones look better when they are pretty much by themselves. I'd try to avoid ANY gap, even if it means getting cabinet filler on the sides.

I like the wider pyramidal shape rather than the chimney as well.

Thanks! So, my original plan was to have a white hood, I was going for minimalism, with the stone splash behind it (Ijen Blue). I can do a custom size of the first Blue Star pictured above to fill the 39.5" (I can't do filler because there are multiple panels to mimic inset and they would no longer match) but if the butts right up to the cabinets stainless might look better than white? (or I suppose I could go bold and match the deep blue in the stone). Thoughts?

What are the cabinets? And other stuff? That matters for color. :P

I would go for a vertical sided hood, no angles, no awkward wedge shapes. (That would mean filler would be simple. But custom is better, natch!) And since custom, fill the gap. Like this, but with cabinets to the ceiling, and uhhh...better:

The cabinets are Brookhaven nordic white with slab doors. The counters are Ijen Blue, hardware ash gray and faucets polished nickel. Floors are natural white oak. The overall vibe is modern but not comtemporary.

Another option, though also not cheap, would be to change the flanking cabinets to 18", opening up more space around the hood. I think two new wall cabinets would probably cost about the same as custom sizing a Blue Star or Modern Aire hood. I don't mind the extra $$$ as long as it looks good. (I'm thankful I didn't have the hood purchased before we found this dilemma).

Below is another example of hood #2 from above but I would do it without straps. It would be nice to not have to do a custom size, but I'm not confident this is a good look. I'm terrible at making these kinds of decisions! :(