Honestly id just grab an 850w and not stress too much about the 1000w models right now. I went through the exact same headache last year when building my rig for sim racing and ended up with the Corsair RM850x Shift 850W 80+ Gold. It handles my 7800X3D and a power hungry gpu without breaking a sweat, plus the side cable design is super nice for tight cases like yours since the desk placement means you dont want fan noise driving you crazy in VR. The 3080 pulls plenty of power already, but 850 watts still leaves you a comfortable overhead cushion. Unless you plan on dropping a ridiculously power hungry halo card next gen, you wont hit the limit. Way back when I cheaped out on an undersized psu for an old i7 setup and had random shutdowns during heavy endurance races, ever since then Ive been real conservative about staying well within safety margins. Gold efficiency keeps things running cool and quiet which matters a lot when your headset is right next to the machine. Save the extra cash from skipping the 1000w units and put it toward your next gpu fund instead.