"Can anyone suggest something that's really going to sound great?" Yes: all the pre-amps you listed. It's the room, and the monitoring. SOS magazine famously did a blind mic pre-amp shoot-out years ago, with well-known (and expensive) mic-pre's losing out to a . . . ART pre-amp, the Pro MP II, which is a two channel pre costing around 400 bucks. I know you're talking about a converter with mic pre's, like the Focusrite 18i20 (I own two of those, and all our drums are recorded on one of them), but still, and obviously, the name on the front of the device can influence one's perceptions. I use an ASP 880, eight channels plus inserts, reliable indeed for around $1400.00, at my main studio. If someone blind-tested the Focusrite and the ASP 880, I'll bet I'd be hard-pressed to hear a difference, and what kind of difference would I hear? In the SOS test mentioned above, a few test participants were shocked at how "bad" the expensive kit sounded.