be quiet! is an excellent brand. You can't go wrong with either choice, but I'd take the extra wattage.

The 1000W one based solely on it being ATX3.0 which is much better if you plan to stick with it.

I'm using a 650W PSU from be quiet (the straight power series) and I'm using more power consuming compoments than you are (R7 3800X + 3070) and I don't hear my PSU. I know you said you want to overspec but honestly save yourself the money, get a good be quiet one and that's it

If you're underusing your PSU, that's also not good since its efficiency will be worse. But if that's no concern for you then feel free to go for the overspec

I have a hard time believing that the PSU fan is the one you hear the most when pushing the system. They usually have pretty big fans in them so they can move a lot of air without crazy high RPM, similar to case fans. But your CPU and GPU on the other hand... usually smaller fans which means a lot more RPM to get the CFM needed to cool. Especially if you are using an Intel stock cooler... Stock CPU coolers SUCK.

That said, to answer your PSU question... You generally want to live around or under 80% of the rating of the PSU, as it is most efficient. Which typically is easy to do: based on quick calculations and making generous assumptions for your system, the PSU you have is likely enough (estimated true power draw of all your components mentioned is around 500w, likely just under. And that is assuming you are pegging every single component all at once, which is unlikely to happen through normal use. 500 / 0.8 = 625 or 620*0.8=496W).

My advice is filter down to brands you trust, and then look at modular units, and then buy the most wattage with a good 80+ rating that you can afford within the budget of the system you are trying to build.

If they are the same price you'd be insane not to go for the be quiet! one! ATX 3.0 and 1000W will set you up for a long time.

850W is absolutely enough for anything you throw at it (even a 4090), but the Corsair one doesn't have a 16 pin GPU cable.

Go with be quiet!, it's an awesome brand :)

Gigabyte may have some on sale.

If you can afford it, Dark Power 13 1000W, oterwise the Pure Power 12 1000W as a second choice.

In my opinion, get the Corsair.

That PC will pull about 300W at full load, maybe 500W if you take transients into account so both those PSUs are valid options in terms of power, in terms of quality they're both good, so unless you can get a very good deal on the be quiet, the Corsair is probably the best choice.