My original plan for power brakes was to use a vacuum pump to provide vacuum to the existing brake booster. Jon Volk (@tesla_bimmer) posted about using an iBooster instead in his conversion so I started researching it. It is purely electrical booster and you can talk CAN to it to integrate it into your regen setup. You can run it in failsafe made without CAN to just be an electrical booster. Here is a great source about the iBooster and also for the hard to source connectors.
There is also someone on eBay selling the connectors. I picked up an iBooster from a Chevrolet Malibu Hybrid since it was much cheaper than the Tesla ones. I’ll have to confirm the pinout is the same as the Tesla.
I’ll have to see how it fits and if it would be possible to to just reuse the E46 master cylinder or if I’ll need to re-pipe it to use the master cylinder that comes with the iBooster.
Anyone need a vacuum pump?