[Flynnster]

No experience here but a few ideas from other experience.

For the vent fans. If possible, have the actual fan near the outside of the building, pulling air thorough the ducts. This takes a much bigger fan, but works better and it really cuts down on the noise. This is how restaurant vent fans work so well.

Another thing, some lounges I've been too seem to be focusing on getting rid of the smoke smell with oder eater type machines that simply recycle the air and treat it as it goes through.
It always seems better when the ventilation is simply set up to get rid of the smoke, pump it out, and bring in fresh air instead.