Sixshot

So my nephew is wanting a gaming PC for Christmas, and I have an extra PC that I use to run a stream on, but it ended up having very little use. I'm going to clean it up, add an extra SSD, and maybe put some new fans in it. Its got a venerable RX570 in it, which should be fine for the game he really wants to play, "Hearts of Iron 4". He really likes the RTS genre. I have an extra of the same card, new in the box, and was wondering if there really would be any benefit to do Crossfire with RX570s?

I've got an original Centurion 5 that's in great condition (Was my first case). The I/O panel works fine and is in good condition, but is outdated. I would like an almost identical panel, but with more modern ports. Has anyone here ever had a custom part fabricated for a case, and if so are there any recommendation of who to go with? I would need the not just the metal frame, but new ports and connections. Attached a picture of the original I/O.

I'm hoping someone can answer a newbie question for me. I'm planning to do dual pc streaming setup, and I've decided on a Ryzen 7 3700x for my streaming pc. My question is, for a dedicated streaming pc, will the stock cpu cooler be sufficient or should I go with a beefier aftermarket cooler? Still new to all of this, so I get lost pretty easily on what is necessity and what is overkill.