Exactly- a passive intake doesn't use a fan.

Active intakes can add a whole new level of complexity and problems. You have to match airflow pretty carefully between active intake and active exhaust- More intake than exhaust will stink the place up, and an underperforming intake will limit exhaust cfm.

A passive intake ( that's large enough) will balance according to negative pressure created by exhaust.

I like can inlines for the bulletproof factor, and low operational noise. Also, they pre-package fan&filter for a couple bucks less than a la carte- so you know that they'll match.

One thing to keep in mind when comparing fans is static pressure capacity, if you need it for long runs. The inlines move a bunch of air assuming a low static pressure, but capacity drops pretty quick when air pressure on the exhaust side exceeds intake pressure- you know, like when you're blowing into a tube.

Squirrel cage designs maintain much better airflow against pressure, but chew a bunch o' watts doing it.

Different designs for different purposes.