Thought I'd post a small update: so I've tried doing a few configurations, and I can't find a full set of Bitspower anywhere. Like literally nobody has more than a few bits of the same color in stock (I've checked most EU wide shops and some where I've bought before like aquatuning). Caseking are going to supposedly receive some earliest on the 31st, but at this point I'm not sure anymore. Thanks to the suggestions here I thought I'd get a few rotaries and the valve from BP as they have the best track record, and for the rest either to HK + straight barrow fittings or a Bykski block and all BP.
Does anyone know if any decent US vendor ships to EU? At this point I guess I might as well tank the import duty just so I can get a build going, I still need fittings and a CPU block and the stocks situation here isn't going to get much better.