Many people have had success matching ARC preamps to Bryston amps (I am one of them) but if its a "warmth" you are looking for those ARC preamps with 6h30 tubes (LS-17/26/ref3) to name a few won't give you what you are looking for. Older ARC preamps that use other tube sets will better serve your need and offer the opportunity to tube roll unlike those with the 6h30 tube. I really like my ARC LS-26 mated to my Bryston 7B-SST2 amps but it does not provide a "warm" presentation...
Cannot recommend if there is an ARC preamp that will give you everything your "require" in a single box as I am not familiar with their older models but my guess is you may end up with another solid state preamp if you need to get all those options into one chassis.
Cannot recommend if there is an ARC preamp that will give you everything your "require" in a single box as I am not familiar with their older models but my guess is you may end up with another solid state preamp if you need to get all those options into one chassis.