I’ve owned the SWL 9.0 SE twice. It is a much thinner sounding preamp than the others you are looking it. IME not Dan Wright’s best work, and I’ve owned nearly everything he’s made. Consider his LS100 instead.
I bought a Loki but returned it after a couple of weeks. Did not care for it at all. I find it to be a beer budget sound. Funny though, I bought a Bellari EQ570 to replace the Loki and I like it so much better.