Inline fans should be set to pull air out as exhausts; adding an active intake actually is a waste, and can even interfere with the efficiency of your exhaust, because turbulence decreases air flow.
With a nice big unobstructed intake hole, you don't need the intake fan.
Hang your exhaust fan in midair from thick soft rope to dampen vibration and de-couple it from the structural members of your apartment. Use flexi duct to get the air where you need it.
Thanks for bumping this thread, it should be a sticky in growroom setup and I'm moving it there.