I have an SSD connected to mine which doesn’t need external power and runs fine off the “official” power adapter. The case I have isn’t the greatest (two pieces of acrylic and some stand-offs lol), but it costed 50p and gets the job done.

As for scale, you’re beyond a Pi at that point.

Maintaining a browser is an insane amount of work. Without Mozilla working on Firefox, LibreWolf will stagnate and become unusable.