Do you have the kids yet?

Or are you making plans for the future?

There are lots of bike trailers out there. And, probably newer and better ones every year. A good bike shop or sports store should have a few. Also consider whether you wish to get the stroller attachment.

Pristine trailers show up on Craigslist and thrift stores from time to time, and the old ones get converted to cargo trailers.

Anyway, perhaps try hauling cargo now. And, wait for the final trailer decision until the kid is closer.

If you're car-free... perhaps you could use a trailer with very young kids, but I'd be reluctant to use one for a kid less than 1 (pre crawling/walking).