"tired of getting associated with prebuild noobs. " Huh? Good grief. Tell those people to get over themselves and remind them that you have a nicer computer than theirs.

The PSU does not confirm to ATX 2.2 standards. Besides the EPS pin being an 8 pin connector with only 6 pins being wired up, you will also notice most cables that plug into the PSU have 6 wire connections instead of the 8 wire you would expect.  24 pin MB power connector does not conform to the ATX standard, it is a custom pin layout. Here's a guy who has done this with an R11. As you can see he explains it really well, and it's a struggle for sure: https://forums.redflagdeals.com/dell-alienware-aurora-r11-r10-3080-3090-mod-thread-cooling-case-swap-2445451/   Also keep in mind not all modular cables are supplied with the PSU, like you would expect. They only supply what your system uses.   You can scrap that 1000 watt power supply because Dell has customized it to their own liking instead of following the worldwide standard that most other computer manufacturers follow. They simply don't want you to use these parts anywhere else and have customized multiple things to make your life difficult should you try to use these parts in another build.   Another thing they have done is customize the motherboard. The IO shield does not confirm to the ATX standard, and forms part of the chassis. While the MB itself mounting wise does confirm to the ATX standard, you will need to cut room in your new case for the IO shield. If you are doing that you will have to mode the PSU over with it, because a 'normal' PSU will not work with this board and might damage it.   If you are planning on moving the AIO liquid cooler over, the hoses are abnormally short. Customized for this case. Moving this over to another case might not be possible.   Fans form another issue, because the motherboard only accepts a few select aftermarket fans. Trying to start up with something else might result in an error message during boot.   There's also the custom power case switch, the custom USB MB connectors etc...   Personally I would strip the CPU and Video card from the Alienware and purchase all the other required components. It's just not worth the hassle dealing with all the customized parts and layouts and not worth smoking new components with all the customized cabling and pin layouts.   Unfortunate, but this is the way Dell wants it.