What can be used to make Bluetooth headphones configured via SPP?

Question

Bluetooth

I want to make bluetooth headphones that can be configured through the phone, watch the battery charge, autopause and other features. I suppose to use a microcontroller and an external audio processor or DSP, although the documentation for many chips contains all the features I need, but nowhere is it indicated how to use them.
The question is, is it possible to transfer music and commands in parallel? If so, on what module or chip can this be implemented? Previously, I assembled headphones on the CSR8645 module, I was faced with the fact that there is no information about the firmware, writing programs for it. I don’t want to spend hundreds of dollars on dev kits, I still do it for myself, and not for production.
There is no time limit, I want to figure it out, but I don’t know from what angle to approach.