I worked on a similar greenfield project around the same time and we looked at RabbitMQ and Kafka, eventually going the RabbitMQ route. We were also developing

I worked on a similar greenfield project around the same time and we looked at RabbitMQ and Kafka, eventually going the RabbitMQ route. We were also developing an on-prem COTS product, and zookeeper played a big role in our decision to go with RMQ, not to mention at the time CloudAMQP had a very generous free tier (not so much anymore, but it's still okay-bordering-decent). No one install would ever hit the scale where Kafka makes sense so I still think it was a good call pushing 10 years later.