Throw me your opinions! (Bass amp head/ Cabinet)

Depends on your desired tone. Like many, I started on a Fender Rumble 100. I’m sure it’s fine if you play modern stuff. It’s in arguably terrible for blues/blues rock.

Think outside the box. I got a 15W all tube guitar amp that’s just insane how good it sounds. There are no bad tones on it. Yes, on a guitar amp. Unless you’re playing outside or in large space without a PA system, there’s a good chance you won’t ever need 500W, let alone 800W+.

Caveat Emptor, YMMV, different strokes for different folks, etc, ad nauseum, ad infinitum.