What type of battery are you planning to use? Have you thought about what supervisor should fit all the requirements? Also, a lot of features will require a lot of power consumption, that means that you need to be able to dynamically turn on/off different peripherals (that why btw SOM will suit your goals better than plain RPi, even it has decent wifi and bluetooth modules).
The current battery in prototype is LiPo 1600 mAh. You mean we need high discharge battery that can deliver lot current in peak moments?
Have you thought about what supervisor should fit all the requirements?
Actually not yet. Can you advice something?