I've been looking at hoods too (see other threads) but not at the capacity you need. A 48 inch BlueStar pumps out, what? 100,000 BTUs? That means you need at least a 1000 CFM hood, likely more. A quick look at the usual internet retailers shows that you'll need to spend--drum roll--a ridiculous amount of money (to me). On the other hand, you're getting a Blue Star, and I have a GE, so maybe your idea of ridiculous and mine are different. :-) Good luck.

Ikea sells some "L" shaped stainless shelves that are hung on the wall with a metal french cleat system. However, what the drawings show in the pdf for step 1 is screwing a big plywood 1/2 of a wood french cleat to the wall. They say that this mounting plate is included. The insert is then screwed to the liner in step 2. In step 3, Brackets are screwed to the insert+liner. Then, the insert + liner is attached to the cleat on the wall by screwing through the brackets in step 4. The brackets don't use the cleat at all. Step 5 shows the other half of the french cleat mounted on the back of the decorative cover. It looks like they split the cleat into two sections with a gap in the middle. When they slide down again the wall, they are caught by the first cleat by the opposite angles. I don't think they bought anything special. The metal of the liner is all you need to protect the wall. Here is a link that might be useful: Ikeadom.

I am the resident expert only because real HVAC systems engineers don't frequent this forum, as far as I know. Noise introduced into the kitchen will be significantly reduced if an external blower with silencer can be fitted. A lot of the high frequency blade tip turbulence caused noise will be removed. This is also true of an in-line (duct mounted) blower. The issue of the neighbor is difficult to assess. What is the configuration of his or her windows relative to your potential external blower (1500 CFM I assume you meant). Your own window sound transmission is also an unknown. Generally, the external noise could be abated by (a) using a silencer on each side of a duct mounted in-line blower, or (b), using a deliberately under-driven* "up-blast" commercial blower (mounted as a side blast). (I think opaone is using an under-driven blower for his new system.) It is also possible to use a chase to move the blower up to roof level. I have a 1500 CFM nominal Wolf (Broan) blower on my roof. Its sound level is detectable but not obtrusive from the ground, but it might be if in a wall location where the sound is "trapped" between two houses. Possibly a more expensive but similar in design Abbaka downslope unit would be marginally quieter. ------ * commercial blowers of this type can use a pulley system between motor and fan that allows for different ratios. By choosing a ratio that operates the fan blades below their rated speed when the motor is receiving maximum voltage, significant turbulence noise can be avoided. The physical cost is a larger unit than would otherwise be required for the desired flow rate. Residential blower fans are directly coupled to their motors.

The detailed answer is "it depends," and if you want to deal with the impracticalities of adaptation, an existing hood could be covered. Lets review what these separate devices are. A metal (always) hood is designed to operate above flames and hot cooking devices. Its functions are capture, containment, and to be a fire stop. High quality hoods overlap cooking plumes adequately, have sufficient flow rate for containment, use baffles for filtering and fire stoppage. Hoods generally have polished sheet metal that is exposed and use relatively invisible welds. What does an insert have to do -- the same functions. However, what it doesn't have to do is look nice on the outside, as that will be covered. What does it have to do in addition: Keep the exposed wood cabinetry from being directly exposed to fire hazard underneath. For this, the insert should overlap the wood at the bottom. As might be apparent, to use a regular hood within a cabinet requires added sheet metal to keep cooking plume effluent from getting into the area between hood and cabinet. And it needs sheet metal added at the bottom (probably the same sheet metal) to protect the exposed wood. I don't have an insert type hood, so there may be other details of which I am unaware. I would suggest, however, that you not try to adapt a hood. On top of meeting functional requirements, you have to deal with code enforcement. Code enforcement generally works not from engineering arguments presented by the home owner tying to save a few bucks, but from comparing the installation to the manufacturer's installation manual. So any DIY's planning to design their own insert hoods are advised to get formal permission first from their municipal code enforcement officers. Note: Picture A is of an insert hood. Very likely Picture B is of a full metal hood for which the exterior metal is fancier than usual.