Island hoods are 28" deep...and probably another 1" to keep it off the back wall. Unless very high, you are going to be taking it in the forehead. Is this chimney hood requirement driven by your dislike of the wall hood design, or because you don't have cabinets or a soffit for hood support? If the looks of the wall hood are acceptable, you may want to look at making due with a 12" stainless steel chimney cover off the top (either made or sourced from another hood company) if that is the look you need, or with full width (48") stackable chimney covers. Here is a link that might be useful: ApplianceAdvisor.com

On the subject of installation. The hoods are generally heavy, so one should plan to have suitable joists or cripples above the ceiling to bear the weight. One hopes that the manufacturer will supply suitable screws. If not, use long, self-boring, structural screws (they use T type bits). In the picture above, we can guess that the hood is tied to the duct covers by sheet metal screws or bolts and nuts, depending on weight. The apparent (and apparently very custom) duct covers, in turn, are attached to roof area beams. Internally, the ducts rest on the hood structure and do not provide support, but rather depend on support. The bigger problem results from having the beam parallel with the long axis of the hood. There usually isn't enough room in the hood top to construct a counterpart of the design above. In such a case, it may be necessary to be as custom as the above, and adapt a more commercial style layout such that there is enough front to back room to pull off a concept such as above. The duct out the back and up is an interesting variant. The duct and/or duct cover would not provide suitable support. Perhaps wires or pipes or some other scheme could bring the weight of hood and ducting up to the ceiling. Some effort would seem to be needed to make it presentable. kas

"We have 9 foot ceilings, so they didn’t take them to the ceiling because they said it would make them tall and skinny..." Really? I call BS. Here are my cabinets to the ceiling with 9 foot ceilings. I am beyond happy that my cabs go to the ceiling, eliminating the need to dust above them. My kitchen looks larger and brighter without the dark shadows above the cabs, too. My cabs are custom so we were able to spec 46" uppers with 8" crown but you can go with 42" tall uppers and 12" crown. I asked but you didn't answer: is there a reason why you haven't considered moving the fridge to the sink wall? That would give you wider aisles and a larger island, plus more room around your range and a better meal prep flow of fridge to sink to counter to range. I mocked up how that might look. You can use your existing fridge (that saves $$) and pull the base cabs out to create 30" deep counters, which will make your full size fridge look like a counter depth model. I decreased the depth of the cabs on the opposite side of the kitchen to 12" deep for a full run of pantry cabs. You may be able to eliminate more uppers in your kitchen with the additional storage the pantry cabs provide, which means that you could make the window over the sink even wider. Here's how that might look in your kitchen. I didn't draw it up this way but your one window would become either 2 slider windows or 2 single hung windows or, as they did in the above kitchen, 3 single hung windows. I shifted the island away from the sink counter, giving you 45" aisle between counters (42" between fridge door and counter) and 42" aisles between pantry cabs and island (assuming that your kitchen is 13'/156" wide). That also gives you more room around your range so a wider range and hood would look more in scale. That said, I agree with others: an oversized hood isn't the right fit for your kitchen. I also think it's an odd choice to spend so much $$$ on a very detailed, oversized hood over a 30" range. I think it will look like you ran out of money half way through the remodel so all you could afford was a 30" range, not the 36" pro style range you had intended to get. And definitely spend the money to upgrade to drawer bases. That's a splurge that you will never regret. Ever.

Lynn wrote: "I can't find any information online about this idea ... I'm sure I'm not the first person to think of it." Assuming Houzz/Garden Web counts as "on-line," then your search missed a key source. You will find here that this subject has been exhaustively addressed, both with respect to down-draft vents and ceiling "hoods." tl;dr: Cooking effluent rises as a plume starting at pan diameter (larger with gas) that expands as it rises. The hotter it is the greater its momentum. Hotter, higher momentum plumes cannot be effectively u-turned to flow downward to a vent. Only the lowest temperature cooking can be deflected in this way. As for collecting the rising effluent at the ceiling, plume expansion and effects of cross drafts cause the ceiling vent to have to be very large and have high CFM ventilation requirements, along with high CFM make-up air requirements. Perform your search with the "site:" tag pointing to here.