I’d stay away from some of the very boutique brands. If you decide to move on you may find it hard to sell. If I were you I’d go for Audio Research. It’s well built, is desirable on the used market and sounds terrific!
Audio Research made a lot of different preamps. They aren't all the same. I have an LS 26. It's very nice but it's not in my main system. If I had a Ref 5SE or higher, that might be in the main system. I had a Modwright LS 100 in the main system for a long time until I recently replaced it with a "boutique" Herron Audio VTSP-360. It's a keeper.