Sounds like you know what you want. The only unit that seems to be in play is the Great River. Maybe consider the Portico, an actual Neve preamp, instead?
Very interesting to listen to these preamps and go back and forth. At first it seems like they are the same, but then you can start to hear the subtle differences. On the source material used in the sessions, I would have to say I liked the API's the best, followed closely by the Portico.