Intel server case with 8 hot swap 3.5" bays for $200 with free US shipping

[nabsltd]

6-pin to 4-pin fan conversion: I found a 4-pin fan adapter I ordered and am waiting to try out (https://www.amazon.com/gp/product/B07BWFT253) that I think will allow me to use the 4 pins while not destroying the fans 6 pins. I have to look more closely at the power differences mentioned above

You'll definitely need to use some sort of power injector with PWM lead as referenced. Each fan draws nearly 2A at full speed, so a single fan header will not power 5 fans. I went with this 10-way with power, but I think I'll end up with what @FlorianZ recommended, as that will likely be cleaner looking.

The front panel is usb-2...anyone found a usb-3 conversion or replacement front panel that will work?

I went with this USB 3.0 and audio panel, and put it in a 3.5" in 5.25" adapter. Why the two-step? Because the tool-less 5.25" bays need to connect to two sets of holes, and most 5.25" front panel units only have the front set of holes.
You could use something like a rear panel bracket for USB 3.0 and put that in place of the two ports on the front panel, but you'd have to find something that fit exactly.

CPU cooler: I had to remove the Noctua NH-D15 chromax. Black, Dual-Tower CPU Cooler

The Noctua NH-C14S fits and is probably better than the Silverstone.

 

[RyC]

I'm still running one of these from the natex s2600cp/kallyomalley deals back in 2016 and I love it! It's a very solid case like @Marsh said.

AUPBEZEL4UF will turn this into a 4U rack mounted server case (if you find the rails) by replacing the front bezel, adding handles to the front, and turning everything horizontal, and AUPBEZEL4UD is a replacement security door (although both seem expensive now)

 

[nabsltd]

I've had enough of a chance to play around with PWM on the fans in the case. Up to 35% they are quite reasonable and are still able to move a lot of air. At 50%, they are probably too loud for right next to you, but if you set that as your "next to max speed" using your fan control software and tie it to whatever temperature you feel is the "gotta get it down, even if it is a bit noisy", you shouldn't be too annoyed unless you run at that temp all the time. Then, set 75% to 100% PWM for the "drop dead" temp that you never hit.