I do not see why you would need something deeper then that for a nice kitchen that is not over the top. Yosemite sells several 36" wide units that are 300 cfm rated. They sell to retailers only I do not have my books with me but my memory says the dealer cost is 75-150 they charge us shipping if we order one at a time. I would think you should be able to find many things available for 300 or less. You should state what you feel is reasonable to help sift the answers to match the questions! I would expect total cost as a dealer of about 225 on the more expensive units including shipping. I am waiting on the catalog for broan. I finaly found a local wholesaler who I can work with that stocks broan products. I would tell you about them if I had better numbers at hand.

I had a 6" height restriction and venting issues as well as requirement of twin fans for a 1000 cfm. Imperial hoods (manufactured in California) met all of those criteria plus additional custom features. I suggest you call the the manufacturer direct with your questions. The office folks know a great deal but will send you to their engineer if stumped. You might also try the appliance forum for assistance.

You can’t violate the clearance to combustibles required by the manufacturer. Ranges have to have the doors and seals protrude, so as not to catch the adjacent cabinets on fire. There ARE a few ranges designed to more less be flush. Designed for looks. You give up power. There are trade offs to everything. You can’t have it all. Decide if you want a usable kitchen that you make pretty, or a pretty kitchen that you can‘t wok fry, only steam fry. And smoke up the house doing that. If you want a powerful cooking top, that’s a rangetop, or range. Not a cooktop. You can’t have it all. You have to accept tradeoffs. And that range needs to be against a wall. Not on an island. So that some of that cooking vapor has help to channel into the capture zone. You can’t have it all. You have to accept tradeoffs. With a powerful hood, and makeup air. And if you choose island cooking, a bigger and even more powerful hood, and more makeup air. You can’t have it all, you have to accept tradeoffs. Cooking is only 10% of kitchen activity. Prep is 70%. Cleanup is 20%. Islands are most valuable as large social prep spaces. Not hot, unsafe, and too small for prep, crowded cooking and prep zones. If you choose island cooking, there are ways to do it that are both functional and safe. They take more space and cost more than putting the cooking zone on the owe meter. You can’t have it all. You have to accept tradeoffs. For island cooking, that’s a lot of added expense added as a tradeoff to do it right.

Carl wrote, in part: "... we are at the tail end ... " Sorry that you missed the note somewhere that the entire kitchen as a system needs to be defined before buying anything and particularly before defining cabinets and cutting duct paths. The kitchen system has to include both the hood system and the make-up air system. Both of these can (in some cases) be relatively non-complex, but one has to analyze air flow requirements and components that achieve them in order to know what to buy. I can recommend parameters that will achieve sufficient air flow in most cases, particularly including hot oil cooking. These are the same as recommended in myriad topics here over the past decade or so, and should have been reviewed when thoughts of kitchen ventilation first occurred. High school math is needed. In summary, for capture the hood has to overlap the rising and expanding (i.e., conical) cooking plumes that are emitted over the surfaces of pots and pans. A 10-degree angle to vertical may be used.* Side cabinets should aid capture and allow a small reduction in hood width. Cooking odorous stuff in the cooktop center can help. Front-to-back "depth" has similar requirements, except that for wall placements, the wall acts as an extended capture boundary. So ideally, for a 36-inch cooktop, that may have front pan edges at 18 to 20 inches from the wall, a 22-inch or greater hood depth is desirable. The 3-inches each side is desirable. Note that the rising plumes are also susceptible to cross drafts and turbulence from human movement, so bigger than the cone limit is better the higher one sets the hood base. For containment, the air velocity entering the base aperture of the hood has to be high enough to ensure that all effluent is entrained into the flow that goes through the baffles. This varies with the plume velocity, the volume under the baffles, and general configuration of internal reflecting surfaces. I recommend 90 ft/min across the area of the hood base, and this translates to 90 CFM per square foot of hood entry aperture. For blower rating, the fan curve of the blower has to be accounted for vs. pressure losses (air friction) of baffles, hood transitions, ducts, wall or roof caps, and of course, the make-up air (MUA) balance vs. house pressure. As alluded to way up this thread, a factor of 1.5 times the required containment flow rate determined from the paragraph above may suffice if the MUA is sufficient. Duct diameter should keep full power flow velocity (duct CFM/duct sectional area) in the range of 1000 to 2000 ft/min. MUA I will defer for now. If you will edit your word salad into paragraphs I will look to see what questions I missed answering. ______ * The plume is actually a distribution function that varies with moisture and grease content, pan surface temperature, and whether the heat source is induction, gas, electric coil, hot coals, etc. 10-degrees should be sufficient to balance the wider plume "rays" against their more easily entrained lower upward velocities.