Recently I designed a high-level ECU system for Ebike and send it to PCBGOGO company for it's PCB manufacturing and production. they have a good staff there that they did sourcing with good parts as well as good PCB quality, my PCB was two layer, with RF impedance control and immersion gold and Edge plating. they did all of this for me very well. they did 1000 pcs assembly in short time with good quality too.
I think you can choose them for your works ... that's my first experience to work with them but it was good for me.