Can you give me a quick ELI5 on the power supply part? I have minimum knowledge with specs itself but absolutely zero when it comes to how powersupply works within the build. Might consider your suggestion though since it is a small price bump.
It basically boils down to while 80+ Bronze, Silver, Gold, etc., are about efficiency, they have nothing to do with quality.
Some brands are lousy quality, some are good quality, some are so-so.
Within brands, some are good, and some are bad.
Seasonic is generally good - and the S12II was good for its day, not sure about the S12III. However, they are older designs, and while I don't really understand the details of the guts, I'm given to understand that the FOCUS and PRIME models are more modern, and better able to cope with the way modern PCs draw power (I know it has something to do with group regulation and dc-to-dc conversion, but honestly, that's something I don't personally understand and rely on the experts to tell me).
HOWEVER - above all, the PSU is the MOST IMPORTANT part of your system. That contributes to longevity. A high quality PSU will deliver clean, stable power to your PC, whereas a low quality one will not. A low quality one can fail, and take out your PC's components with it. Really bad ones have been known to cause fires.
Another key is to be able to deliver most/all of its rated power on the 12V rail. It's usually measured in amps.
So, for example, if a 480W PSU says it can deliver 39 or 40 amps on the 12V rail, that's 468 or 480 watts (watts = amps x volts). If it says it can, for example, deliver only 28 amps, that's 334W, that's an immediate red flag. It probably makes up the rest of the power on the 3.3V and 5V rails, which, while they are necessary, are minimally used in modern PCs. The 12V rail does the heavy lifting, and should be able to provide most/all of the power that the whole supply is rated for.
Ultimately, though, there are people and websites that, through analysis have examined and rigorously tested numerous power supplies. They're the reason I know what bits that I do.
TL;DR: it's like setting up your PC to play "Russian roulette" - with a high quality unit, you're assuring there are ZERO bullets in the gun. The lower the quality of the PSU, the more bullets there are in the cylinder.