No controller needed, unless you want to slow them down. Something like this will allow you to use any standard 12v barrel plug power brick or wall wart. Add a few molex splitters to allow you to run a silly amount of fans as long as the rated amperage of your power supply is decent. Assume worst case of about 0.5 amps per fan, so for 4 fans you'd want at least a 2 amp 12v supply.
[Breakout Board]
Was not looking to use a big atx pc power supply with the molex pins so I searched Amazon and found this $5 adapter:
https://www.amazon.com/gp/product/B07FK5XDY6/
I plan to pair with one of the 5.5x2.1mm barrel 5V 3A wall power adapters mentioned in this thread.
​