For my own build, most areas have a 4 meter ceiling. Two decks have a 4.5 meter ceiling, which in retrospect I feel is excessive, and the lowest ceiling is probably 3.6 meters.
The build has a respectable amount of traffic, caters to a number of larger avatars, and I have never had anyone suggest these ceilings were too low.
I imagine that 3.7 would work fine if camera issues are all that you are worried about. However, standing up from furniture can create additional issues. Though, you may be able to solve that with a simple unsit script which drops the avatar in front of the furniture, rather than
SL's default of tossing an avatar upwards.