Hello.
I can create circuit and pcb for it according your requirements. I can do it in AltiumDesigner or Diptrace, as you want(I prefer to use Altium Designer). After completing I will send you all project files, library, documentation in pdf format(schematic, layout drawing, assembly drawing, BOM, etc..), 3D model of your pcb, and gerbers for manufacturing.
I have a few questions:
1. You need to power this device from automotive power source or only charge LIPO from it?
2. Do you need external connector for antenna or need a small ceramic build-in antenna to pcb?