Cryptocloaks sells a kit starting at $260 which includes a nice case and adapters. You can add on the 3 fans for +100

https://www.cryptocloaks.com/product/s9-bitcoin-space-heater-bundle/

If you wish to fully DIY I believe kaboomracks (contact them on telegram) sells the s9 with braiins preinstalled for $125

This is prob the best guide I've found (pdf download):

https://www.cryptocloaks.com/download/44528/?tmstv=1701194482&version=v3

I use these fans, which are probably same as what CC offers:

Need 2x of these:

Noctua NF-A14 iPPC-3000 PWM, Heavy Duty Cooling Fan, 4-Pin, 3000 RPM (140mm, Black) for Desktop https://a.co/d/1BKXFIP

Need 1x of this:

Noctua NF-A6x25 FLX, Premium Quiet Fan, 3-Pin (60mm, Brown) https://a.co/d/cQiWREt

You may also want this adapter for the psu if you dont want to solder:

CRJ Mini XH 2.5mm 2-Pin Female to 3-Pin and 4-Pin PC Fan Adapter Cable (2-Pack) https://a.co/d/1Ox2ad8