UK 5080 Build Comparison

I’ve done a fair bit of shopping around and want to go for a 5080 build with a 9800X3D. The UK market is fairly grim at the minute but it is what it is. I’ve narrowed the best offers down to these two:

https://www.costco.co.uk/Computers/Desktops-PCs-iMacs/AWD-IT-Phantom-7-AMD-Ryzen-7-32GB-RAM-2TB-SSD-NVIDIA-GeForce-RTX-5080-Gaming-Desktop-PC/p/554524

https://www.overclockers.co.uk/refract-gaming-indigo-1440p-4k-pro-pre-built-gaming-pc-fs-1dn-ep.html

The Costco one has a B850 motherboard and 850W power supply, and is £2800.

The Overclockers one has a B650 motherboard, a 1000W power supply, and is £2900.

I’m not that bothered about min maxing on cost. After building a PC in the past and having to troubleshoot I just want peace of mind.

I’m leaning towards the Costco one. Does this make sense? Should I be prioritising the power supply instead? Are there any other offers that are just better than these?

I was able to get an okay deal on AWD-IT that had both the B850 and the 1000W, but I really didn’t like the case and didn’t have the option to change it.

Thanks and apologies if this is a super common question.