We found things through: Buggy Revival, DePop, charity shops, Ebay, Freecycle (emails may go to your spam folder), friends and family, GumTree, Mummybay, Nextdoor and Preloved.
Start 4 Life baby moves information
Buggies, prams, push chairs, strollers, travel systems
The more ethical brands seem to be: Bugaboo, Joolz and Venice Child.
Carriers, slings, sling hire
Used from ebay
General used car seats from ebay