I love Amazon Warehouse for items like these. I recently bought one of the 400cfm vortex fans (used-like new) and 2 of these
to cover the whole work area. They are now around $25 a piece but when I purchased them from Amazon Warehouse they were only $11 so I couldn't pass them up.
I will be putting a piece of clear plastic I have left over from a DIY projector ceiling mount I made to cover the top holes (I considered insulation like used on keezer builds around the collar as well) with the hood over the BK having a cut out for exhaust. I will use a 45* angle connector to the hose to keep it as low profile as possible. The hoods have two screw holes on the sides to bolt them together and then I will use a pair of clippers to cut the metal in between to make one large 5 foot hood.
This will exhaust out of my dryer vent I have in the same room. With the 400+ CFM fan I have read condensation is not a problem at all so I was not worried about a lip for condensation drip.
So overall cost will be roughly $110 or so with the connector and hose I still have yet to buy. I also trolled craigslist for some range hoods and found one similar to your first link that someone was trying to get rid of for $100 but they were 3 hours away so I didn't jump.
Hope this helps at least to give you ideas of outside the box hoods.