So far the way we were supplying power to our system was only "quick and dirty". The Pi would be powered by a phone charger. All other things would be powered by usb cables cut open and connected to an usb hub. Cables everywhere and very little control over max current and so on...

After playing around and learning about linear/switching voltage regulators, we came up with a system that seems to do the job just right. It consists of a 12V 5A power brick (the ones used for laptops) and switching voltage regulators that power all parts of our system. The power circuit is integrated into the PCB.