If my Asus Thor II 1200w Platinum didn't have an OLED power display then I would have upgraded to a Seasonic Platinum (they make the Asus Thor PSUs). Smaller budget then a Corsair Platinum 1200w. Sorry but a Razer Katana PSU wouldn't be on my list. Razer make top quality but very expensive laptops, some good keyboards & mice, gaming speakers, not sure what else without going onto the Razer website.

I don't understand why their still bringing out non-atx 3.0 PSU's without the new GPU power connectors.. It's kind of buying yesteryears tech if you buy these now (IMHO) I was specifically looking for them and there is only a few to choose from - personally I would not bother with anything less then the "new" standard if your upgrading now. My Corsair RM i1000 was still fine but since I was updating my rig, the PSU had to be switched for my 4090 as I really did not like the massive splitter cable setup. I am (fairly) sure AMD will have these (new GPU power connectors) on their next gen as well, and then your "stuck" with your older PSU and adapters. Unless you don't mind the clutter, I guess you'll be fine, but it aint for me :P

You're right, some PSU manufacturers have a single GPU input on their new ATX 3.0's, some don't. Corsair do provide a 600w GPU cable which is a more important element than the single input on your PSU. I chose a last gen Asus Thor Platinum PSU which came with a 600w GPU cable but has two connectors at the PSU. And if your case isn't wide enough then the GPU cable could end up being bent too much as it leaves the 4090 (unless you've bought a CableMod 90 degree adapter). But at least a 600w GPU cable avoids the ugly (and possibly dangerous) twin adapter that your 4090 manufacturer provides.