Tim Watts wrote

Who makes good domestic UPSes these days?

Depends on what you call good.

Looking for about 500VA (need to put a power meter in to be sure) and 30
mins runtime.

Why do you need that long ?

But it's more about which make and possibly series are any good?

Depends on what you call good, particularly
how well it lasts over time.

Would like a decent output too (proper sinusoidal).

Thats mad. Everything just rectifys that.