"I've never heard the Cary SLP98, but I, personally, do not consider my SLP05 to be warm."
I have a Cary SLP98 and it is warm, but also rather thick and sluggish, and was replaced by my own version of a Don Sachs-style Aikido 6SN7 preamp, which is much faster and more transparent but still rich and warm. Unfortunately Don has stopped making his Aikido preamps, and the Tubes4HiFi SP14 it was based on is good but really a DIY project and not as refined as Don's version. For the OP, I would look at a 6SN7-based preamp for the combination of heft, detail and complete lack of distortion that that tube exhibits. The LTA MicroZOTL, Icon's Pure Valve, even the Black Ice Fusion.