Would these also work on a RasPi and cgminer-3.6.1 (I used in the past on the HEX16 boards...)?
No, you need to use newer cgminer & apply the latest patch.
Latest patch is for cgminer 4.6.1.
Thanks, for the (super-) quick reply!
And do I need a PSU with 4 separate cables? Or would 2 cables with the integrated splitter (so 4 PCI 6pin connectors, 2 per cable) work too?