The Aurora R12 PSU is standard ATX format  . . . which means 86mm wide x 150mm tall; and the lengths will vary. The R12 OEM PSU is 140mm long. You should try to find a PSU that is 140mm long, because anything longer will start to take up your cable management space. The Corsair RM 1000X is a good PSU, but it is 180mm long. It will fit, but you will have less room for cable management. You should also consider a fully modular PSU so the cables that you do not need can stay in the box. The 3rd party PSUs need to be able to fit a wide variety of case sizes, hence . . . the cables are long when you put them in the Aurora nano chassis. Be sure to have some zip ties. Here are some fully modular, 1000 watt, 140mm PSUs from pcpartpicker  (click photos to embiggen) This is what my 140mm PSU looks like [IMAGE]   This is the Doghouse's 200mm PSU [IMAGE]
So I'll try to keep this brief. I'm looking to upgrade an Aurora R12, starting with the PSU. I've done some research myself but nobody seems to give anything too concrete on which PSU would be compatible with the system due to it using specific sizes. I'm told that the recommended part has the numbers "0WTGN" and that "D1000EGM-00" is the PSU used, but unless I'm missing something I'm having trouble finding a PSU that really matches these. My searches primarily lead me to the Corsair RM1000x, but nobody can 100% tell me if that'll work, so I'm going to ask here and see if anyone else has experience. Thanks to everyone who reads this.
Aurora R12, help with upgrading PSU