Ok thats a bit outside of normal bench top power supplies and starting to wander in to something like a Mean Well RSP-500-12RS. I would also recommend capping off the connector area like you see done on some 3D printers...
You would need a supply capable of delivering more than 432W regardless of which voltage you go for, so I would ballpark working with 500W plus (I haven't checked startup current so you may want/need to go bigger or stagger the fans starting up to keep peak draw to an acceptable level)
Edit: spelling corrections, again...