New Preamp Suggestions

I have an M3A full function preamp. I have had it and an M3 over the last 15 years. When I first purchased the AI, I wanted a tube preamp to balance out my SS power amp. I now have a pair of Quicksilver V-4's. The problem I am having is what to shop for, especially since there are so few full function preamps, even if I go to $5-6K. SS, Tube or trade up to an AI 3B (at considerable savings about 50%)? Also does it make sense to spend that much money on a linestage and get a budget outboard phonostage? I also haven't heard a M3B yet and don't know if it mostly a lateral move. Obviously I am not unhappy with the AI, but I want to try something of a newer design and this will likely be a last preamp purchase.