I've used this one for someone who couldn't duct out. You don't need a lot of CFM if you are just trapping the grease and blowing the hot air back into the room. We actually had a short duct that came out near the ceiling in that installation.

She hasn't had any trouble with it, but honestly I don't think she uses it a lot. What is the reason you can't vent to outside?

Here is a link that might be useful: Faber

You're doing this backwards. You start with the insert, and then design the hood to fit around it. You may have fit issues doing it this way.