as I said, no eves so I can't go anywhere but roof. Which I spose I could do. little leery of what a 4" hole saw is gonna do to old fiberglass shingles. I guess with enough flashing and goop it shouldn't be a problem.
The Whisper doesn't seem too expensive. 80cfm would probably be ok, but I think I would go with the 110. and rated at .5 sones pretty much has be sold already.