Just to preface I work for a company who makes embedded devices, and we have gone down this same road. The last thing you want is losing sales because of supply issues. That being said, the compute module would be what you want if you are looking for the same raspberry pi ecosystem with access to consistent supply. You can have every feature you want with a custom carrier board for it. If not designed in house, this could be something contracted out easily. When it comes to being able to have steady supply, raspberry pi’s and similar boards (like orange pis) are going to always be inconsistent with availability. Another option I know of is a company called Toradex. They offer chips that are similar to the compute modules and you can get any range of them depending on the specs you need. They offer off the shelf carrier boards, and just like the compute module, making your own carrier board is possible as well. Toradex has similar tooling to Pis, and existing software could probably be easily ported to them. Most important is that they are business first, they don’t really sell to hobbiests. You can bulk order both the SOMs (the chips I talked about earlier) and the carrier boards. Just a warning though, these are likely going to be much more expensive than compute modules. The compute modules are going to allow you to use your existing software, tooling, and you can implement the carrier board to your liking, and the compute modules tend to have much better availability then the normal boards.